Latent fingerprints

Introduction [00:00:01] RTI International's Justice Practice Area presents Just Science. Welcome to Just Science, a podcast for justice professionals and anyone interested in learning more about forensic science, innovative technology, current research and actionable strategies to improve the criminal justice system. In episode three of our case study season, Just Science sat down with Dr. Michael Nirenberg, a clinical and forensic podiatrist and current president of the American Society of Forensic Podiatry, to discuss how analyzing a perpetrator's gait and footprint evidence located at a crime scene can help advance investigations and resolve cases. While locomotive characteristics like the way our hips swing when we walk are not as individualizing as fingerprints or DNA, forensic podiatrists can analyze and compare video footage of a perpetrators gait to a person of interest gait to develop supplemental forensic evidence. This additional information can be used to support a conviction for the exoneration of a falsely accused individual. Listen along. As Dr. Nirenberg describes the role digital evidence plays and gait analysis, how forensic podiatrists analyze and compare the gait of a perpetrator to a person of interest. And several cases where the analysis of gait or footprint evidence were key to supporting investigations. This episode is funded by the National Institute of Justice's Forensic Technology Center of Excellence. Some content in this podcast may be considered sensitive and may evoke emotional responses or may not be appropriate for younger audiences. Here's your host, Mikalaa Martin.
Mikalaa Martin [00:01:35] Hello and welcome to Just Science. I'm your host, Mikalaa Martin, with the Forensic Technology Center of Excellence, a program of the National Institute of Justice. On today's episode, we will discuss several case studies demonstrating the value and utility of footprint evidence located at crime scenes, analysis and the subdiscipline of forensic podiatry. Joining us today to discuss these topics is Dr. Michael Nirenberg. Welcome to Just Science Dr. Nirenberg.

Dr. Michael Nirenberg [00:02:05] Thanks for having me.

Mikalaa Martin [00:02:06] So, Dr. Nirenberg, to kick us off, can you tell us about what it means to be a forensic podiatrist and your journey to this forensic subdiscipline?

Dr. Michael Nirenberg [00:02:15] So I was a podiatry student. I wrote a article on forensic podiatry, and that was published in the Podiatry Journal at the time. And in that article I wrote it just because I was interested in how podiatrists using their knowledge of feet and the lower limb, which is what podiatrists focus on. We treat the foot, the ankle and the lower limb. Using that knowledge to help law enforcement solve crimes and or help a defense attorney show that their client is not the criminal. And so I wrote that paper back in 1989. And in that paper, I said, we need an organization to promote knowledge, ethics and whatnot related to forensic podiatry. And a short time later, the podiatrist doing this called me up and they said, we're we're forming that organization that you called for. We want you to join us. And I did join, but I told them, you know, I'm trying to start a practice and I'm too busy. And eventually I ended up being on the board. And now I'm president of that organization, which is the American Society of Forensic Podiatry. So the American Society of Forensic Podiatry is a relatively new organization. It was started in the 2000s, I believe. And what it does is it promotes knowledge and education for podiatrists and actually non- podiatrists who have an interest in feet, footprints, and gait. Podiatrist focus on biomechanics, disorders of the foot and ankle. Using that and combining it with forensic science to answer a legal question, usually a criminal matter.

Mikalaa Martin [00:03:57] Throughout your career in forensic podiatry. You've been called as an expert to provide multiple types of analyzes in criminal cases. What are some examples of the roles you have assumed and the expertise you have provided on these cases?

Dr. Michael Nirenberg [00:04:11] Some of the cases have involved footprints where you have a homicide and there's footprints left at the crime scene. For instance, there was a case in Maine where I testified where a woman had been stabbed just shy of 500 times, and there were two people charged with the crime. Law enforcement asked me to take a look at the footprints at the crime scene to help figure out if either of these two individuals or both could have made the footprints found at the crime scene. In that case, we obtained the footprints from the suspects. And that in itself is an entire process. And then I compare the footprints with the crime scene. And I was able to show that one of the persons charged with the crime could not have made those footprints due to a various number of reasons, including the size of the footprints at the crime scene versus his footprints. And I determined that the other suspect, a woman who was also charged her foot, could have made those footprints for someone who has the same footprint as her. And part of educating the jury is explaining how footprints are distinctive and well two people in theory could have the same footprint. The odds of that are typically low. And at this case, there was other evidence provided for both of these people. And ultimately, the jury could not decide with the man if he was guilty or not. And the woman was found to be guilty and she was sentenced.

Mikalaa Martin [00:05:46] And among other forensic analysis types, perhaps under- discussed or even underutilized is gait analysis. Can you explain what gait analysis is to our listeners?

Dr. Michael Nirenberg [00:05:56] So gait analysis is something that clinicians, medical people, podiatrists and scientists, researchers they do gait analysis and gait is how an animal or a person moves from place to place. It's a locomotor activity. But in the forensics and in the clinical context, when you're talking about people, gait is typically how we move from one place to another. And that can be walking, that can be running, that could be hopping. It could all be a form of gait. But in the forensic context, when we look at gait analysis. We are looking at walking usually and we're comparing one person's walk or the how that person walks at the crime scene to a suspect or a person of interest, how how that person walks. And you're making a comparison and you're looking at that person's manner of walking or their gait literally from head to foot. And there's a process to that that we can talk about. But in a nutshell, in the clinic, people are looking at gait or doing gait analysis to figure out perhaps what's wrong with that person's shoulder or biomechanics or how can we make an orthotic, an arch support a brace to help them walk better? And then forensic gait analysis is doing a comparison of the features that you see from head to foot of a person and comparing that to another person. These are usually cases where their face is not clear or not visible or where a person says That person may look like me, but that's not me. And then law enforcement or a defense attorney might say, I need some additional information and gait is that additional information. Traditionally, gait has been overlooked. There was a case involving gait where a scientist in the 30s determines the criminals gait from shoes, I think boots left at the crime scene, and he described how the criminal walked in detail and in court they had the criminal walk and he walked exactly the way the scientist had described. But forensic gait analysis is involving video and looking at how somebody walks on videotape. And now we get more and more what they call CCTV. So we're getting more gait footage and forensic gait analysis. The first time it was used by a podiatrist was in the video since was in the year 2000, in the United Kingdom, where a podiatrist helped to show that a jeweler was the same person as a known suspect and he was convicted. So it's sort of growing from the year 2000. In the United States in 1996, a dancer who was very attuned to how people walk and move helped identify somebody at a crime that was on video. So it was used here by someone with some knowledge of movement in 1996. It has evolved now to a more peer reviewed standardized process, which goes back to me working with OSAC to help get that process fully developed. But the methodology now has been peer reviewed, it's been published, it's been tested. We know its reliability.

Mikalaa Martin [00:09:16] I appreciate the background and how it's evolved. Can you walk us through with no pun intended there the comparison process and any of the tools that are used in that comparison process?

Dr. Michael Nirenberg [00:09:28] The comparison process involves using a checklist, and we call it a tool, and it's called the Sheffield tool, because Professor Birch, out of the United Kingdom, he with some peers, came up with a checklist of features that are commonly seen on video to compare. And that checklist evolved from clinical medical checklists. So people looking at gait can use when they do observational, they look at someone's gait with their eyes. They have different tools that have been published, peer reviewed and check for their reliability. Those tools work. Meaning if two different doctors, Mikalaa, watch you walk on two different days. Those two doctors, to a certain degree of reliability, will be able to use one of those tools and show what's wrong and what's right with your gait looking at certain features. So Dr. Birch and his associates basically took that concept and said, you know, if it's working for medical researchers, let's translate that to the forensic context. And they looked at the features that tend to show up on video and they listed those features and then they went and they did testing. They published it. They did more testing. And they showed that this is a reliable way of determining, you know, looking at someone's features of gait. So how do you do it? Well, you start by getting video of a crime or a crime scene or a criminal. And you can't say, for instance, you don't know their face and you go through from head to foot looking at that videotape, figuring out all their features. For instance, does their left foot tilt in tilt out or is it straight? Does their knee hyper extend at a certain point in what we call the gait cycle? And you do this for that piece of footage looking at their head, their torso, their arms, their elbows, their hands, their hips, their knees. And you look at all these different features literally from head to toe and you get this tool filled out. And what makes forensic gaitt analysis work and what makes it interesting is you don't just look at one step. You need footage of the person showing multiple steps. Because when we walk, we repeat the same pattern. With each step we take a step. We go where our right foot moves forward, then our left. Then we're back to our right foot. That's one cycle in the gait cycle. In simple terms, we would like to see multiple steps of somebody walking. So when you're comparing if on one step, their arm doesn't completely swing, you're looking at multiple steps, multiple gait cycles when you do this. And that's ideal. If the footage only had one step. I would tell them like, I can't help them.

Mikalaa Martin [00:12:22] So from that overview, it sounds like while gait analysis can provide helpful information on a case, it sounds like there's some things that it cannot be used to inform. Can you speak a little bit about that?

Dr. Michael Nirenberg [00:12:33] So the important thing to keep in mind with forensic gait analysis and this is something that I'm often telling law enforcement detectives and sometimes a detective will call me up and say, I know it's him, and you can tell by how he or she walks and gait in the context that we do it in the forensic gait analysis context. So looking at a piece of video, it is not unique. What I mean by that is people have distinctive mannerisms when they walk. And each mannerism, whether their their hip swings in a circle or straight ahead, that motion is what's considered a class characteristic, meaning there are a lot of people in the population whose left hip may swing in a circular manner when they walk, and that is not at the level of DNA. But what we do do is we're going from head to foot. So each feature is a class characteristic and you stack those on top of one another and you get a higher level of discrimination. But at the end of the day, gait in this context is not unique. Gait in the laboratory where you put little sensors on every joint in someone's body and they're digitized on to a computer screen, that may reach the level of being unique. But at this point, what we're doing is class level characteristics and we're stacking them on top of one another. And as you do that, it becomes more discriminatory. The important thing is that you're also looking for a feature that would rule out them being the same person. So, you know, and this is just a very simple example, and I wouldn't want this example to come back to a specific case I work on. But just as an educational example, if that criminal needs hyper extend when his foot hits the ground, meaning the knee, our knee should not move backwards when our foot strikes the ground. But some people have knee problems and their knee will hyper extend with every step. It sort of bounces backwards a little and that may be for both knees. And you have somebody who's a suspect whose knees never hyperextended. In fact, they don't even extend all the way straight. Their knee is always bent a little for each foot when it hits the ground. So that would be a significant difference. And that would start to lead us down the path of the gait of these two people is different. Now, what I get at this point a lot of times is couldn't somebody just change their gait? And if you've seen a fashion show, of course people can change their gait runway models. I don't think they walk like that when they're doing the laundry. So they they change their gait. But the thing is, is that one forensic gait analysis is not widely known. A criminal may wear gloves to hide their fingerprints because that's pretty widely known. But and they may and they may wear a mask to hide their face because they know they can be identified by their face, but they don't think to change their gait when they walk. So so it is unlikely that they're going to change their gait. It may happen at some point, but when somebody is changing their gait, you know, a experienced forensic gait analyst or even somebody who does gait gait analysis, a lot may be able to look at that and go, something is not actually something is off here that the person is doing. And and if they do do that, you may not be able to use forensic gait analysis. If somebody is just jacked up on five hour energy. I had a armed robbery that I worked on where the lead detective, it was his only case in his entire career he told me he could not solve and he finally figured out that one of the criminals walked the same as a known perpetrator in his in his area where he worked. And so he had me come in to compare the gait of three people. It is violent armed robbery and one person was just jumping around. His gait was erratic to the point that you couldn't compare that gait with anybody else. So I don't know if he was on five hour Energy. I don't know if he was on drugs. I don't know if he was just excited to be doing an armed robbery. But he was just jumping around and it was so erratic that guy couldn't be compared. Now, another guy, the guy, the other person, the other two people at the armed robbery, their gait could be compared and they weren't erratic. But you could get that. If somebody's on drugs, you just may not be able to compare their gait, you know, depending what you have there.

Mikalaa Martin [00:17:12] And you have already given us a couple of case examples where gait analysis has been used to support cases leading to prosecutions. However, it's also been used to support exonerations. Can you discuss a case where gait analysis supported an exoneration?

Dr. Michael Nirenberg [00:17:28] I was involved in a case in New York State. What happened in that case was I was brought on because a man who apparently didn't have the funds at the time for for a high level legal counsel, he was convicted of a kidnaping in 2013. And it was there was a place of business involved. And they sent me it came about through one of these government programs to look into exonerating people who may have been wrongly convicted. And what I did was I looked at the gait of this person who visited the business at that period of time, and I compared it to the gait of the kidnaper, who also visited the same business that the same period of time. So these were two African- American men. And on the surface, they their body types and shapes look similar. But once you compare their gait, you saw their gait was very different. And this video of this kown person walking in and out of this place of business, as well as the kidnaper, this was all done way before he was charged with the crime. So they said it was the same person and the jury found him guilty. And so I wrote a report and there was another report involving showing his cell phone was not at the business at the time of the crime. And there may have been some additional information. But the the judge in New York exonerated him, I believe, in December of 2022, and he was let out of jail immediately. So in the documents that I was sent later, it showed that they referenced the I believe, the judge, as best as I can recall, referenced that gait analysis was part of her decision. So she looked at my report. So that felt pretty good because to me, it's more important in my for me to to free an innocent man then convict or help help free an innocent man than to help free help convict a guilty person. It just feels more meaningful to me.

Mikalaa Martin [00:19:38] And from that example, in a couple earlier case examples that you have provided, it sounds like with gait analysis, having other information or evidence in the case can support it. Can you speak a little bit to the importance of having additional evidence and case information?

Dr. Michael Nirenberg [00:19:55] Mikalaa that's a great question because I think I mentioned earlier that gait is not unique. And so when I get a detective saying I know it's him by his gait or how he walks, I always immediately tell the detective that you need more evidence than just gait analysis to convict somebody because more than one person can walk the same, even though there is all these different features that we pick up with people. And so I always tell the police right up front, if this is your only evidence, I'm not going to be part I'm not going to knowingly be part of having someone convicted based on gait. Gait can exonerate by itself and show these two people do not walk the same. And that creates a large amount of doubt. So I'm up for that. But to to participate in having someone convicted based on on gait by itself, wouldn't it be it wouldn't be fair for the for the for the person charged with the crime.

Mikalaa Martin [00:20:56] And as you've mentioned, the gait analysis hinges on digital evidence, such as surveillance footage or CCTV being available in that case. How does technology such as surveillance footage enable you to perform gait analysis?

Dr. Michael Nirenberg [00:21:09] So cameras are becoming less expensive and more prevalent. And we're using cameras more and more now in society law enforcement, people's phones, they've ring doorbells and the quality of the footage is improving with time. Sometimes you still get footage where the quality is low, the resolution or the frame rate. So. With good quality footage, you'll have a higher frame rate. You'll have more frames in a given instant of time. So you can see more detail. I actually had a case where they had drone footage looking at someone from above. You know, when you look at someone from above, some people will twist from side to side when they walk. There's different features of gait that you can pick up from above. In an ideal scenario, you'll have

a crime scene with multiple cameras. You know, there's three planes. When you look at the human body, there's the frontal plane and then the side plane and then sort of coming straight down on the person. And if you have multiple cameras, that helps because you're seeing more aspects of the person's gait and you can put all three views or cameras together. What the problem with technology and cameras is that the people who sell the cameras are not the people who actually, at the end of the day, need to use the cameras. So I get sent a lot of footage where the camera was placed in a really bad position because the salesman, they never really have to analyze the footage of anybody. And I imagine a better camera company, at a minimum, would get a police officer or law enforcement involved in the camera's placement. So I see an improvement in the placement of these cameras coming in the future as these companies realize we need to give more thought to what these cameras are being used for at the end of the day.
Sometimes there's just a lot of cameras that don't show you much usable footage. Even even if you see people who get robbed in gas stations and whatnot. A lot of times the camera doesn't really show you much of the criminal just because of the place of the camera. So I see that improving in time. I see the quality improving. I see more cameras coming about and I see hopefully law enforcement beginning to recognize that gait can be used to assist in a criminal investigation.

Mikalaa Martin [00:23:38] We have previously discussed the use of footwear impression evidence on the podcast. However, you have supported many cases where footprint impression evidence played a crucial role. Can you talk to us about the distinctiveness of footprints and how footprint impression analysis is completed?

Dr. Michael Nirenberg [00:23:56] What I do is footprints analysis, and I don't look at the ridge detail that a fingerprint examiner would look at. I look at the overall shape, the morphology. I consider the biomechanics of the foot that made the footprint, and I consider some other factors as well. So if there is ridges, if there is region detail or dramatic glyphs, I would tell law enforcement, you know, you need a fingerprint expert perhaps to take a look at that. But I will look at the footprint, the shape, the size, the position of the toes and the biomechanics. And there was a there was multiple studies done by the Royal Canadian Mounted Police, by researchers there who ultimately determined that the chance of a match of a footprint is something to the effect of 1 in 1.2 billion. Now, that is under laboratory conditions, not necessarily in the real world, but it does give some measure of the distinctiveness of footprints in the real world. It may not be that high, but our footprints differ again because of our heredity, our biomechanics. Spend the day with me in my podiatry office. I see 30 people. I see 60 feet. Assuming no one's had an amputation. And you know, every foot is different. Even our our left and right feet have been proven scientifically to not be mirror images of one another. So even a lot of people will say my feet are different sizes to that difference. But I've looked at I did a study on looking at identical female twins, and even their foot impressions in footwear were different. So over time, due to injury, due to some people wearing poor footwear, they've shown that women who wear high heels in their early part of their adult life, in their 20s, for instance, and then they stop wearing them later in life. They'll have more foot problems as a result of that than a woman who did not wear high heels when they were younger. And I'm not telling women not to wear high heels, but I'm just giving an example. I think as a podiatrist, high heels are like if you're on a diet, having Haagen-Dazs ice cream once in a while, you know, it's like a decadent treat, put on whatever. But just to show you that it takes a toll on your foot, it can change your foot later as you age and different things develop as you grow older and injury and putting on weight, losing, having being very slim, being underweight, neurologic diseases, medical problems, diabetes. There's a lot of things that affect our feet and make our feet distinctive. Again, not unique distinctive.

Mikalaa Martin [00:26:35] On the topic of case studies. You presented a lecture at the 2024 International Association for Identification or IAI Educational Conference entitled Footwear to Feet: how a killer's feet were connected to shoes found at a homicide. Can you speak to how an association from a perpetrators foot can be made to their footwear?
Dr. Michael Nirenberg [00:26:57] So the way we connect or disconnect, the way we show a connection between someone's foot and footwear found at a crime scene is not necessarily by looking at their footprints. We do consider their footprints, but the main thing we do is we compare the shoes the suspect has on his feet at the time he's arrested or questioned by police. So, for instance, in Canada, there was a 14 or 15 year old girl who was raped and murdered in shoes near the crime scene were found. And the shoes near the crime scene had a blood, but the blood was mixed. It was the victim's blood. And there was other DNA found on the shoes. And therefore, the suspect said that these aren't his shoes or someone else wore his shoes or they borrowed issues because it was mixed DNA. And a lot of times with footwear, because we walk around, you don't get just one person's DNA. You get multiple people's DNA on the shoes. So that's when they bring in a forensic podiatrist. And I compared the shoes that he was wearing when he was arrested with the shoes, with the victim's blood found near the crime. And you look at different things inside and outside the shoes. You do an actual what I call a shoe autopsy. It's nowhere near as involved as a real autopsy on a person. But a shoe autopsy, where I look at the wear, I look at the wear patterns, the wear on the bottom of the shoe inside the shoe. And I compare the insole, the foot impression in that shoe to the crime scene shoes. And what's interesting in that case is the person who did the murder wore skateboard type shoes. And the suspect when he was arrested had skateboard type shoes. In Virginia, a guy came home and found a burglar in his home and they scuffled and the burglar stood up and shot him a couple of times and killed him and left his shoe. That shoe left at that crime scene was a basketball Nike shoe. And when that suspect was arrested, he had the new version of the basketball Nike shoe. So it's been interesting that people, at least criminals in a very small subset of criminals that I've had in my life, they seem to purchase or put on a similar shoe and then they wear that. And so the comparison of the wear in one shoe to the wear in the other shoe is stronger. It's a stronger comparison because it's not like he went from wearing a basketball type sneaker, Nike, to wearing, you know, some fancy dress shoe. So you get similar wear patterns in the shoes and you compare those.
Then you look at the person's footprints and compare those. Then you look at the person's foot. And that's the thing that forensic podiatrists do that a lot of other people who look at footprints or compare footwear don't necessarily do and some may do. But podiatrists beyond doing the comparison, actually look at the foot and see how that can relate or not relate to the findings they're obtaining. So in that case, in Canada, I was due to testify and just before I did, they were going to challenge my testimony and I wrote a report showing that this methodology had been done in Canada. It had been appealed to their Supreme Court previously because someone in the RCMP had done something similar. The RCMP stands for the Royal Canadian Mounted Police, and after they got that report, he decided to to plead guilty. In Virginia I testified and that with other evidence, he was found guilty.

Mikalaa Martin [00:30:43] And from the perspective of a forensic podiatrist, and given the multiple hats that you wear within the forensic community, where do you see the field going next.
Dr. Michael Nirenberg [00:30:53] In the future I see gait analysis, forensic gait analysis growing just because of the wide use of cameras. I believe that is going to really weigh large in the future. I know there is a significant need for this. It can be used to assist with defense or law enforcement. It doesn't stand by itself by any means, but it's assistive to assist in investigation. And I see that growing people do not typically use their feet when they do crimes, and they typically don't leave their footwear. That happens now and then. It's not that common, but the forensic gait analysis. That is going to just continue to grow. It's going to become larger. More and more people are reaching out to me to look at footage. The problem and the limiting factor has been is that the footage up until this point a lot of times is just not adequate for meaningful analysis. And I think that will improve just with more cameras getting out there. They'll send me the footage that is not meaningful, but they'll also send me three, four, five more cameras, and somewhere in there I'll have what I need to to do this right for them.

Mikalaa Martin [00:32:06] And for a final takeaway today, are there any identified needs or recommendations you have for overcoming any current challenges or gaps within the forensic podiatry field?

Dr. Michael Nirenberg [00:32:17] I really think we in terms of forensic podiatry, our biggest challenge is finding podiatrists who have the time and energy to learn what they need to learn to do this. Any podiatrist can be a forensic podiatrist, but to do it right, you really need to be a bit of a foot nerd. And I'm a foot nerd. And the people who do this, I would say, in the kindest complementary way, are foot nerds. And I like problem solving with feet. I like puzzling out things. And as a result of my interest in forensic podiatry, I've stumbled into, you know, doing other kinds of foot related issues pedicurists who may have injured somebody, you know, slip and falls at various places car accidents, patent cases, patent infringement cases and other cases, fraud and whatnot. So like, for instance, there was a case where somebody said he was hurt at work and he couldn't even walk. He had trouble walking and he had an ankle injury. And in between to doctor visits, they did surveillance footage where basically he wasn't just walking normally, he was like carrying big bags of groceries and whatnot. He was doing better, better than most people do. So I've fallen into some other things. But the biggest challenge for forensic podiatry is finding a podiatrist who a lot of podiatrists are interested in this and they sort of dabble in it and they find it fascinating and they love learning about it and they love attending lectures and seminars and hearing about it. But to make the leap to start to do it requires that you just learn a lot of forensic science and have that knowledge base. And, you know, people are so busy nowadays that there's not a lot of people who who have the time to put into it.

Mikalaa Martin [00:34:06] Thank you for your time discussing the fascinating realm of forensic podiatry. Dr. Nirenberg, it has been a pleasure talking with you today.

Dr. Michael Nirenberg [00:34:14] Thanks for having me. I've enjoyed talking to you, Mikalaa. I really appreciate it.

Mikalaa Martin [00:34:19] If you enjoyed today's episode, be sure to like and follow Just Science on your platform of choice. For more information on today's topic and resources in the forensic science field, visit forensicCOE.org. I'm Mikalaa Martin and this has been another episode of Just Science.
Speaker 2 [00:34:42] Next week, Just Science sits down with Denton County Sheriff's Office senior forensic investigator Ashleigh Berg to discuss the capital murder case that was resolved through bloodstain pattern analysis and the use of surveillance footage and real time tracking data uncovered throughout the investigation. Opinions or points of views expressed in this podcast represent a consensus of the authors and do not necessarily represent the official position or policies of its funding.

Introduction [00:00:01] RTI International's justice practice area presents Justice Science. Welcome to Just Science, a podcast for justice professionals and anyone interested in learning more about forensic science, innovative technology, current research and actionable strategies to improve the criminal justice system. In episode two of our case studies Season Just Science sat down with Tim Fayle Training Capability Lead for IDEMIA Australasia and Chair of the International Association for Idenifications Latent Print Certification Board to discuss the utility of friction ridge detail inadvertently captured via photographs as a valuable and potentially underutilized type of evidence within a variety of case types. While the use of latent fingerprints recovered from crime scenes has been established as an important type of forensic evidence for decades, the increasingly widespread use of social media and other digital platforms has contributed to even more opportunities to garner friction ridge detail evidence following a crime. Practitioners and researchers alike have demonstrated the value of utilizing photographs, presenting inadvertently captured finger and palm friction ridge detail obtained via social media posts, other digital forums and cellphone data to identify perpetrators and help bring justice to victims. List along, as Tim described several cases where inadvertently photographed friction ridge detail was utilized to make an identification to a perpetrator. The various methods and techniques latent print examiners can add to their toolkit to analyze and compare this type of friction ridge detail and his recommendations for ensuring this type of evidence is not overlooked or underutilized within future cases. This episode is funded by the National Institute of Justice's Forensic Technology Center of Excellence. Some content in this podcast may be considered sensitive and may evoke emotional responses or may not be appropriate for younger audiences. Here's your host, Mikalaa Martin.

Mikalaa Martin [00:01:53] Hello and welcome to Just Science. I'm your host, Mikalaa Martin, with the Forensic Technology Center of Excellence, a program of the National Institute of Justice. On today's episode, we will discuss the utilization of ridge detail inadvertently captured and digital evidence, which is becoming increasingly more common due to the widespread use of social media. Joining us today to discuss this type of possible identifying evidence and its application and a variety of modern day and cold case types is Mr. Tim Fayle. Welcome to Just Science, Tim. Thank you for sitting down with us today.

Tim Fayle [00:02:30] Thank you, Mikalaa And thank you for having me.

Mikalaa Martin [00:02:33] Of course. So, Tim, I would love to kick off today's session and episode with you sharing a bit about yourself and your journey to and through the discipline of forensic science.

Tim Fayle [00:02:44] Yeah, certainly. I've had a bit of a varied experience, shall we say, multiple countries, as you can tell from my accent, I'm from Australia originally. I started in forensics doing a forensic science degree at the University of Technology in Sydney in Australia. I then started working for the New South Wales Police, initially as a Scene to Crime Officer, which is basically a CSI. I did that for a couple of years and then moved into fingerprints in 2005. Again, my expertise in Australia in 2009 also got IAI certified, which is International Association for Identification, Certified Latent Print Examiner Certification, and in 2012 decided with my family to make a bit of a big move and shifted over to California to the Santa Clara County Sheriff's Office in San Jose. So again, as a fingerprint examiner there, I became director of the fingerprint unit there called the Sheriff's Identification Unit and stayed there for just shy of ten years. And right around the tail end of COVID times, we decided that was the perfect opportunity to move our family back to Australia because, of course, travel was so easy at that time. So we did get to experience a 747 flight with ten people and four of them being my family back to Australia and then two weeks in a quarantine hotel, which was, shall we call it, a life experience. And then after moving back to Australia, I began working for IDEMIA as their Training Capability Lead in Australia. We had a major upgrade to the National Automated Fingerprint Identification system here in Australia, and I was responsible for training all the examiners in Australia on the new system. So that's kind of my short bio.

Mikalaa Martin [00:04:21] That is quite the international journey. Lots of the forensic ecosystem that you've experienced from the practitioner side to the vendor side, so that's great. I know that you mentioned the International Association for Identification, so the IAI. So you're currently the chair of the latent print Certification Board. Can you tell us a bit about your role in the primary aims and objectives of the board?

Tim Fayle [00:04:45] Yes, certainly. So the board is responsible for maintaining the latent print certification program for the IAI. We're responsible for creating new testing materials, ministering the tests, marking the tests and maintaining certification registries. We also currently are in the midst of all the certification programs for the IAI and not just the latent print one. Getting the program accredited as well. So as for anyone who's been through an accreditation at an agency, there's a lot of background work with that. So those are the main responsibilities. I've been on the board since 2015 and I've been chair of that latent print cert board since 2019. So I'm in my second and final term as, as chair. It's been very fulfilling professionally. It's it's wonderful to give back. It's a lot of work, as anyone who's on the cert board will tell you. But very rewarding work, I would say at that, too.

Mikalaa Martin [00:05:40] So speaking of the IAI, you recently presented a lecture at the IAI's Forensic Educational Conference entitled Social Media Fingerprints and Other Inadvertently Photographed Ridge Detail. Can you provide an overview of this lecture for us?

Tim Fayle [00:05:55] This lecture was actually I first gave it in 2015 at the Centennial Conference in Sacramento, and it was after my kind of first case dealing with this kind of evidence. And really, it's targeted at evidence that perhaps some examiners are still unaware of. I would hope that more and more examiners are more and more familiar with it as we progress now on to 2024. It's a type of evidence that you could receive in your day to day work. It's a type of evidence that often detectives either don't know about, don't know the possibility for use, aren't even thinking in that space. And so my idea was just to sort of raise some awareness. So as well as the case I worked on and I presented on some other cases that I found that were published in 2015, it was slim pickings. There were only a very small number that I could find, man, that we'll talk about throughout this, who's done quite a bit of research in this, Shane Turnage out of Canada. He was one of the few who had done some research in this work. The case in this kind of evidence sphere. It was really just to sort of raise awareness with people about, hey, this is actually a kind of evidence that you could receive. It's not controlled, but you need to know how to deal with it when you get it. That's kind of the realm of what I was targeting. Now. I was looking, as always, with any lecture for a what you might term a sexy title. So social media fingerprints are so certainly quite good. However, I also found that it didn't really capture every type of a circumstance that this type of evidence could happen. So as well as photographs of friction ridge skin that might appear in Facebook, Instagram, other social media posts, it also include inadvertently captured detail in, say, like a photograph on a phone that's been seized in a search warrant. So I don't know that my title of the talk is it's a bit of a mouthful in the end. And you know, the UK, when they decided to talk about it, just called it digital friction ridge detail, which is probably a lot easier to describe, but that's essentially the building blocks of the talk. And then the talk that I gave this year at the conference was just an update. So I had some more recent case work that was in there in those years. In between, I've also created an online course and just sort of giving an update. There's also been a validation study out of the UK, which was a really important extra step in working this sort of evidence.

Mikalaa Martin [00:08:13] Awesome. And the year that stuck out to me. So 2015, would you say that that is kind of the year that all of this started to emerge or at least become discussed within the community?

Tim Fayle [00:08:23] I mean, certainly for me, as I mentioned, there were a few people who had raised some awareness about it before Shane Turnage in particular out of Canada. Chris Crisis as well had published about a case that he'd worked on. But for me, my introduction to it was really around 2015 because that was the first case that I worked. And that case at Santa Clara County Sheriff's Office we have had a number of police agencies that would submit evidence to us, and one of those being Los Altos Police Department. And I got a call from a detective one day who said he'd found suspect for a series of burglaries that had self incriminated himself on some Instagram posts, basically just bragging about the proceeds of the crimes and everything. But the Instagram account had been set up anonymously so he couldn't trace who had set it up. But in trawling through some of the posts, he found a photograph and he said, Hey, I've got a photograph of that guy's hand. I'm just wondering if you'd be able to identify the guy from his handprint. And it's in this photograph. So for the fingerprint examiners listening in, he said, it looks really good. It's really good quality. So the fingerprint examiners listening in, I'm sure you've heard that before, where your hear it looks like really good quality to me and then you get it and it's terrible. This was not that case. This one. He sent me the image and I immediately said, Yeah, I think we can do something with this. It was a photograph. He was actually trying to sell drugs as well, and he was holding a pill in his hand, which turned out to be a clonazepam pill. That pill, just from the markings on it, on Drugs.com. I could figure that was a clonazepam pill which had a diameter of eight millimeters. So conveniently enough, he placed a scale on his hand to allow me to scale that accurately, to scale as well. Searched it in an automated fingerprint identification system, or AFIS, and got a hit to a person, provided the information after we got the identification verified to detectives and he was able to go and investigate that lead actually recovered some stolen property from that suspect that when I went around for a search warrant on his house. So that was kind of my first introduction into this sphere. That same year was when I first gave the talk at a conference and sort of triggered my interest in looking into this type of evidence.

Mikalaa Martin [00:10:28] Awesome! And you mentioned that there were a couple additional cases that you had spotlighted in your presentation this year that also came out kind of prior to that 2015 date. Maybe after that 2015 date, would you be able to talk a little bit about those additional cases as well?

Tim Fayle [00:10:45] So there had been some published in Evidence magazine. Chris Gross, I mentioned, had published a case that he had had that was a search warrant photograph where a suspect who was not allowed to possess firearms was holding a gun in a photograph and was able to identify the person from that. Some of the more recent ones that I talked about in the talk at this conference, there was one that probably a number of latent examiners may recognize from 2018 on chat forum called CLPEX.com. A photograph was posted that site saying, Hey, every examiner, can you search this? We need to know who this person is. And essentially, they were sexually abusing a three year old girl and there was a photograph of some abuse and some ridge detail of an index finger was visible in in that photograph. These images had been uploaded to a dark web forum that pedophiles obviously liked to frequent and so detective had found it, had sent it to some examiners. They did not get any identifications from their searches. So they thought, well, let's try everything we can, because this was a particularly heinous criminal who had done a lot of very bad things in the pedophile sphere for a very long time. And so it was posted to this chat forum. So a lot of examiners will probably, if they were to to see the image again, they'd say, I recognize that I searched that back in 2018. So when the guy was eventually arrested, everybody got reverse hits. That was in 2019 when he was eventually arrested. So they did end up tracking him down by other means. And but everyone got reverse hits on it after the arrest. But that was one that a lot of people would probably be at least somewhat familiar with because of the posting on that forum.

Mikalaa Martin [00:12:21] I appreciate you sharing these two case studies, Tim. I find that they demonstrate the utility of this type of evidence and a variety or spectrum of case types. From these two case studies alone, it sounds like this type of evidence can prove to be recoverable and valuable in any case that contains digital evidence. So in your response, you also specifically called to any fellow latent print examiners who may be listening in today. For that audience, what are the main takeaways for modern day latent print examiners? Does this type of evidence bring about the need to expand the toolkit of traditional analysis and examination techniques?

Tim Fayle [00:12:59] I personally think so. First of all, awareness, as I've mentioned a few times, awareness is the key. So just being aware that this type of evidence exists that you can use it, you can get identifications from it, and these images are not to set up where the person is placing a scale on their finger and photographing their finger with the purposes of having it identified. So it's very different to, for example, a live scan capture of a fingerprint where it's a controlled environment, right? It's controlled with the capture of that. It's a known scale. In these images. You don't have a known scale. So having the awareness about the type of evidence, having the awareness about how to use this type of evidence as well. So, I mean, if you have a suspect, a 1 to 1 comparison is fairly straightforward, but not all the time. Sometimes the ridge detail is not facing the camera.
Matter of fact, that happens quite a lot. And so it could be trailing away in one direction or another. And so being able to understand the techniques that are available to be able to correct that perspective issue, that that's present in the image so that you can make a 1 to 1 comparison. And then if you don't have a suspect or if the suspect is not identified, being able to search that in an AFIS system effectively and accurately with an accurate scale is critically important. So knowing how to scale the image correctly, how to know that you are within the tolerance that exists for being within correct scale so that you know that your search has been accurate to hopefully obtain an identification. If a person in the database that you are searching, those tools are very necessary. I would also say even further than just the analysis of evidence is the knowledge set to be able to have a conversation with detectives and even other investigators. So like you, CSI, who are at a crime scene or get a search warrant who come across something like this so that they know when they come across this type of evidence that it is the type of evidence that can be submitted to the fingerprint unit and can be useful in the investigation. I think those aspects are really important today's age as well.

Mikalaa Martin [00:15:02] You mentioned the importance of scaling quite a bit in that first key takeaway. And so to tie this back to the first case study you highlighted today, what's fascinating to me is the out of the box thinking to look up the diameter of the clonazepam pill as a way to scale the image with this concept of ridge detail in informal or inadvertent photographs where a scale is likely not included or maybe is included in a nontraditional way. What methods can latent print examiners employ to recalibrate the image to correct the scale?

Tim Fayle [00:15:33] I've narrowed it down to three major ways to do that, and the first one is kind of what we discuss with the clonazepam pill. So if in the image there is a an object with a known size and it's in the same or very close to the same plane as the ridge detail, then that known object size could be used to to recalibrate your image to scale. So a good example being that pill. Another example being the case of crisscrosses that I mentioned earlier, where the gun was being held by the offender. That gun, you could tell from the markings what make and model the gun was and any make and model known of the gun you can look up the sizing of the various parts of that gun as well. So so that is one way. So a known object within the image. But but the key there is it's got to be close to the plane of the ridge detail that you're targeting. Otherwise you scale is not going to be accurate. The next way is, is a way that Shane Turnage has published on and it's using average hand dimensions and these so he's published on and he's got a nice cheat sheet available for it where it's got average sizes of each of the flanges, each of the sections of palms. So using that, it may not be super accurate, but what I have found through my research and others have found through their research is that AFIS systems have a pretty high tolerance for error margin in accuracy of scale, to the point where I found there were only issues if the scale was out by plus or minus 20% out of correct scale. That was when I started to see a negative effect on the AFIS searches. So there is quite a decent error margin built into AFIS systems and the searching algorithms with accuracy of scale. But obviously with that in mind, you want to be as accurate as you possibly can be. That's the second method is by average hand dimension size. And then the third way is by a ridge count. Espouse book, quantitative and qualitative. I forgot the exact title, but most people note is as the QQ book. His book talked about the average width of friction ridges, and so you can use that information to do a ridge count of I would say you want to target a minimum of ten ridges and preferably 15 to 20 if you have that many. They should be parallel ridges and preferably with as few ridge breaks as possible. So as few bifurcations and ridge endings breaking up the flow of the ridges as possible. You obviously want to avoid curved areas as well. So straight parallel ridges if possible, getting a ridge count and then using that spells average width to figure out the size and the scale from that. And I've had very good success with that as well. So those are kind of the three methods that could be used to recalibrate an image to scale in this circumstance.

Mikalaa Martin [00:18:18] And going back to that first option, you mentioned the importance of plane. So how can latent print examiners adjust perspective for ridge detail on a non perpendicular plane?

Tim Fayle [00:18:29] There's a number of different options there. And Photoshop is hopefully a tool that most examiners are familiar with and have available to them. If Photoshop is not available. There are some tools in other programs. I'm less familiar with those, but I do find the ones that I've seen they tend not to be as powerful is or is as good with this particular issue as the Photoshop tools are. So the three kind of tools and they kind of in order of ease of use, but also the harder they are, the more powerful the tool is as well. It always seems to be the way, right? Like you would love for a tool to be both powerful but very easy to use. But it's not always that way. So there's one called lens Correction in Photoshop, which is a very simple one where you can just basically correct the horizontal or vertical perspectives. Kind of like if you think about rotating a globe, it's

that kind of thought to it. The reason it's in Photoshop is to correct any distortion from know. For example, if you've used a fisheye lens and objects are distorted in the image, you can use that lens correction to just kind of help correct for that. That's the purpose of it in Photoshop. But it can be useful for these circumstances to correct perspective. The next one is perspective crops. So this is in the crop menu of Photoshop and it's called Perspective Crop. And you can basically create a crop you are going with the angle that your friction range detail is on. And then when you click the tick, it will take that angle and make it on a straight plane. The biggest problem with that one is you can't really see the effect of your perspective crop until you click that tick. So there is no like previewing of it.

So it is a little trickier to get used to that one, but a bit more powerful than the lens correction. The last one is unfortunately in Adobe's infinite wisdom they have stopped using the 3D space in Photoshop after version 22 of Photoshop, so I've always highly recommended to turn off your auto updates to Photoshop if you want to use this particular function in Photoshop. You can even have like an older version of Photoshop and the newer version of Photoshop loaded on your computer at the same time. If you have enough disk space, I guess. But it's a filter, it's in the filters menu called Vanishing Point and Vanishing Point allows you to rotate either an entire image or a section of an image around the X, Y, and Z in an Australian or Z axes and not only rotate, but you can also compress or expand on those axes as well. So as well as being able to correct the perspective around to to being much more two dimensional, which is obviously what we're looking at with a live scan or ink to capture fingerprint. So as well as correcting that perspective, you can also correct the unnatural expansion or contraction that will happen when a fingerprint or friction ridge detail is out of correct perspective. So usually if the print is tailing away from the camera, the ridges will be compressed in that area that's tailing away from the camera. And if it's sort of angled more towards the ridges will be more expanded compared to so shall we call it normal compared to a two dimensional capture. So being able to correct for those issues, you can preview what you're seeing when you're using that 3D space. As I say, the biggest problem is unfortunately Adobe has done away with the 3D space in Photoshop after version 22, so if you want to use that particular tool Version 22 is it for you! Those are the three main ones I have actually started investigating and another tool called Perspective Warp, which is available in Photoshop as well. I'm kind of in the early stages of looking into the capability with this particular type of evidence in mind. I'm still in the very early stages there, but if someone wants to have the play around with Perspective Warp as well, my initial look at that seems fairly promising.

Mikalaa Martin [00:22:12] And maybe we'll hear about it at next year's IAI.

Tim Fayle [00:22:16] Yes, I would hope I can do an update there. Yes.

Mikalaa Martin [00:22:18] In keeping with the theme of overcoming challenges and preparing this type of evidence for latent print analysis and comparison with the need to compare social media and other inadvertently captured fingerprint evidence to two dimensional known exemplars. Is it safe to assume many times friction ridge detail is not captured in the two dimensional aspect?

Tim Fayle [00:22:40] Almost always that's the case. The times where it is captured in a two dimensional aspect is and there is a case out of Australia which is a really good one of this, where again, it was a very boastful sort of enterprise by the criminals involved here.

They had committed an armed robbery, they were waving a gun in front of the camera. They were smart enough not to put their face in front of the camera. They had a whole bunch of cash on the bed, you know, kind of waving the gun in front of the camera and the light in the room as the gun was being waved in front of the camera. If you pause the still of the video, the light shone on the gun at such an angle that you could actually see a latent fingerprint on the gun because it was a shiny metal. So that in that case, that's a two dimensional print, right? Because it's a latent print as opposed to friction ridge skin. That was a pretty cool case as well because they were able to calibrate that one to scale via ridge count and search it and get an identification from that print on the gun. But I would say that two dimensional example that I gave would be the exception rather than the norm. It is almost always the case that you're looking at friction ridge skin with this type of images and therefore it's going to be three dimensional.

Mikalaa Martin [00:23:48] And how can that be corrected by latent print examiners in the non oddball cases of having a 2D print?

Tim Fayle [00:23:56] First of all, the accurate recalibration, the scale is very important. But second of all, why that vanishing point filter in Photoshop in particular is so powerful. Because it allows an examiner to not only correct perspective if the ridge detail is tailing away in one direction or another, but as well as that correct the compression or expansion of ridges so that the print appears much more like a two dimensional capture of the same ridge detail would appear. And that's ultimately the goal, right? If we can get the three dimensional friction ridge detail image to appear much more like a live scan or inked captured ten print, two dimensional print is of the same person, well then we're going to have a much higher success rate and accuracy with searching that print and being able to identify it. That's ultimately the goal and the ability to correct for those distortions really mainly around accurate recalibration to scale and correcting perspective in the image.

Mikalaa Martin [00:24:56] So I'd like to talk a little bit about enhancement to latent prints and inadvertently capture friction ridge detail. So for the techniques that are used, are they different from traditional approaches to enhancements made.

Tim Fayle [00:25:09] Aside from things like the perspective corrections I would say not really. It's just applying what hopefully examiners already aware of to the situation. So hopefully examiners are familiar enough with the color wheel and with being able to use like lightens like an opposite will darken. And obviously there's the fluorescent aspects to color, but that's generally not what we're dealing with here. So, you know, being able to use a like color, you know, skin color has a very specific tone in certain races. So it tends to be in a specific area of the color wheel and then either using a like color to lighten that area, if that's what you need to do in your image or dark and out with the opposite color, those are kind of the main sort of enhancements. Other ones that I found very useful again in this sort of Photoshop sort of sphere. If people don't have these sort of enhancements available in their AFIS system would be things like curves, which are great with pretty much any image really, and also levels. In my online course I talk about a specific way of using levels where you can actually target and see what you are removing from the image so that you can avoid removing any ridged detail information. And that's achieved by holding the alt key in when you slide the minimum and maximum bars of levels.

Mikalaa Martin [00:26:28] And one other thing I'd like to talk about is in this era of heavy use of social media times, a lot of times we see photographs that are altered by the poster via filters or even the application of artificial intelligence. Does the use of this type of technology lead to any challenges or considerations for this type of evidence?

Tim Fayle [00:26:49] Yeah, certainly. One of the areas that examiners really need to be aware of is is control of the audit trail of your images. And then, you know, that should be a standard practice with any type of evidence, right? Regardless of the evidence. With this

type of evidence it's the images that especially if they've been posted to social media, those social media sites, all the ones to my knowledge, there is some level of automatic processing that the social media site applies to any image that's uploaded to the site.

Usually it's a compression so that they limit how big the file sizes are that are being loaded on the site for fairly obvious reasons there. But yeah, things like filters obviously available, whether they're on the camera itself of a particular phone or they could be in a software application. You know, Snapchat is famous for having a lot of filters or even the social media site itself might have some filters that you could load it with. So you load an image and you say, I want to apply this filter to it. So those filters, though, by and large, will leave traces in the metadata. So they will be traceable. And the key with this type of evidence is controlling the audit trail for the moment you can, which you can't control from the moment of capture. Obviously. But from the moment you receive it, you can. And so having that audit trail controlled from that moment, and then if there's any question about any alteration that might have happened to an image before you got it, hopefully there would be traces in the metadata. So being able to have the metadata analyzed in those circumstances as well would be important. But it's obviously a concern with this type of evidence. There is a possibility that, you know, an image could be modified before it's posted and some sort of effect to the ridge detail has happened in that case. I would also say for those who have been fingerprint examiners long enough, that type of modification, without leaving an obvious trace of it in the image itself that a fingerprint examiner would be able to see visually would be exceptionally difficult.

Mikalaa Martin [00:28:40] And going back to a theme that came up earlier surrounding education, especially investigators and cases, in your opinion, is there anything that the latent print community can do to educate law enforcement on the utility and value of this type of evidence?

Tim Fayle [00:28:56] Yeah. Conversations, Communications. Like most things in life, right. And especially work conflict, all of it. It always comes down to communication, right? So this is no different. And I would say the key here is having those conversations with your detectives, talking to them about this type of evidence, talking to them about how you can use it if they come to you with this type of evidence, what kind of cases you can use in the pedophile cases, search warrant, social media post for any kind of crime, all of those types of cases, you can have a discussion with the detectives. You could show them examples. There are now plenty of them that have been published. So just doing a Google search on this kind of information, you'll be able to find a whole bunch of published articles about cases where this type of evidence has been involved.

Mikalaa Martin [00:29:41] I love how you mentioned kind of the onset of of cases employing this kind of approach early, early on, starting those conversations. To swap over to the other side of maybe outcomes. Are there any legal considerations surrounding the use of photographed hands and other ridge detail posted on social media or other media platforms?

Tim Fayle [00:30:02] So first of all, there's the legality of obtaining any evidence which applies to, well, any evidence that way we want to talk about, right? So above and beyond that initial legality of seizure of evidence, which by and large the detectives are the ones who mainly have to worry about. The audit trail of those images, as I've mentioned before, is is really critical here. So maintaining that audit trail, whether you have a digital image management system that does that as part of the process that it has for images from the moment it's stored, it archives the original copy. And then you're only ever working with a copy of the original as opposed to the original image. Or if you have to do that manually.

Either way, maintaining that audit trail, if you use Photoshop, Photoshop has a setting to turn on your metadata tracking, so it will track anything that is done to that image that you've done to it in Photoshop in the metadata via that metadata tracking. So that's key. I would also say in the legal aspect like we have with any new enhancement tool or development medium, you know, a new chemical, a critical thing that happens with any of those circumstances is a validation study. So luckily for us, a validation study has been done, has been completed and has passed accreditation and that was done in the UK. And so that validation study was very broad, ranging to very lengthy document. The UK agency that did it is more than happy to share that validation study with examiners, but they passed, I believe it was October 2023. The validation study was was approved through their accreditation assessors. So I would say those those two things are pretty key. And being able to point to that study, maybe having your own internal assessment in your own agency, not a full blown validation study because that's already been done for for start, but some sort of internal confirmation that this type of evidence works in in your procedural set up, I would say is also important. Really, those are the key things to be aware of, legally speaking, in my opinion.

Mikalaa Martin [00:32:02] And a few items I feel and themes that have come up through our discussion. But I would be curious to know in your perspective and in your your journey with this type of evidence and presenting to various audiences and learners for adding this to their toolkit, are there any identified needs or recommendations that you have for overcoming any of the current challenges or gaps regarding this type of evidence in the field?

Tim Fayle [00:32:26] Yeah. So probably my biggest one and I made mention of this in my talk at the conference this year, is making sure that you don't have such a restrictive policy on the receipt of images of friction ridge detail so that you eliminate some of this type of evidence from coming into your lab from the get go. And what I mean by that is, particularly in the US because of, you know what, slow down from the Mayfield era, for example, with latents requiring a thousand PPI minimum resolution to be submitted, at least to the FBI for searching, for example. So having a and I know a number of agencies that have policies like this where they say all images of friction ridge detail, must be a minimum of 1000 PPI, otherwise they will not be accepted. And having a restrictive policy that doesn't even allow an image to be assessed on its own merit is potentially very damaging for this type of evidence. Because remember what I said about social media platforms so often compress the images when they're posted to social media. The control of the capture of these images isn't there compared to a CSI capturing a photograph of a print at a crime scene, or a lab technician photographing a light on an evidence item where they know the camera settings they have to use. They know how to photograph a print so that it's a thousand PPI when it's recalibrated minimum with this type of evidence though that's not the case. Now with the quality of phone cameras just getting crazier and crazier, it tends to be a bit less of a problem these days, but it's still it definitely exists. And so not having such a restrictive policy to preclude receiving an evidence image, if it happens to recalibrate the under 1,000 PPI is really important here. So that very first case that I talked about, the 2015 one out of Los Altos, when I recalibrated that to scale using that Clonazepam pill as a scale, it came back to around 320 PPI. So it would be very much below what most examiners would consider as acceptable. Being either a 1,000 or some use 500 minimum. However, every time I've put that on screen, which I did again at the conference and I said, Who here in this audience believes that this print is perfectly suitable to be used in comparison and to be able to be identified. And well, as far as I could tell, everyone in the crowd raised a hand. It's at a crystal clear, beautiful palm print that we're talking about with very clear detail. It's just a case that the image is 320 PPI. So

I think having a policy that allows you to assess images on their own individual merit and assess if the detail is clear enough to be able to accurately and confidently determine the detail, ridge detail, that's that's visible in the image as opposed to saying hard and fast, No, it has to be a thousand PPI or else. That's my number one recommendation here. And this conversation I had with a number of people at the conference this year and matter of fact, had a back and forth on on email with with a few people is okay, here's our current policy. How could we adjust it so that it's not as restrictive but still making it clear to the people who submit their crime scene evidence to us that they need to maintain a minimum standards for their evidence. So having the verbiage around that, it does sort of force them to do it, what we might say the right way and having the proper resolution for the images they're capturing under controlled circumstances versus an uncontrolled circumstance like a social media post image and being able to assess it on its own merits.

Mikalaa Martin [00:35:59] You bring up a great point regarding the technological advancements that have occurred over the past several years with smartphone camera capabilities. From your own casework, experience and discussions with agencies that have utilized this type of evidence in their cases, could you see inadvertently photographed or friction ridge detail being utilized and cold case investigations, whether that be cases with social media evidence or even photograph evidence from cases predating the current social media era?

Tim Fayle [00:36:29] Yeah, absolutely. Or even the search warrant photos. Right. So search warrant images could go back, you know, 40, 50 years. Right. And not digitally, obviously. But if there's somebody sitting in a cold case folder, an image that happens to include ridge detail in it, then why not? And actually on that front, this is one that I didn't include in this talk, but I did talk about it, the conference as a different case. I presented on a 1979 cold case homicide as the conference as well, where in that particular case and it was very fortuitous. And I always say to examiners, if you have something to present about, even if you don't think someone wants to hear it, there are people that do want to hear it. Please do present at conferences. And one of my best reasons for that was this case. Anyway. When I was putting together the talk, I looked at the autopsy photos and I realized that there were four photographs of the forearm and hand of the victim, and they were taken of I don't know what the medical terms of it, but showing the palm of the hand and then showing the back of the hand so so rotating, but showing the forearm and the hand. And in those images now, these were Polaroids, right? And they were scans of the Polaroids. So I've zoomed into these the hand parts of these Polaroid images, the scans of the Polaroids that I had. And I realized, particularly in the high Pacino area of the palms, there was good ridge detail there and went ahead and compared that to the remaining latents in the case. And lo and behold, was able to identify one of those remaining prints in a very probative area to the victim and ruled that one out from being considered as a potential suspect one. So absolutely, when you're talking cold case, there's a real case example where this type it was an inadvertently captured ridge detail there is no way known that that coroner or the coroner's assistant was trying to capture the ridged detail in that hand. When they photographed the forearm and hand, they were purely just trying to show some injuries that the person had sustained during the attack. But there's a real life example where this can be applied to Cold case. So absolutely, I think it has application obviously in more recent years, cold case work for sure, because you're dealing with digital evidence, you're dealing with social media posts, you're dealing with iPhones and other types of phones, cameras, capturing things. But even the older ones for sure, absolutely can be applied.

Mikalaa Martin [00:38:47] That's an incredible case, especially for scanned Polaroid captures. Thank you for sharing that.
Tim Fayle [00:38:54] Yeah, absolutely.
Mikalaa Martin [00:38:55] Thank you for your time discussing the fascinating topic of social media fingerprints, Polaroid fingerprints, and other inadvertently photographed ridge detail and how this type of evidence can support case resolution. Tim, it has been a pleasure talking with you today.

Tim Fayle [00:39:11] Thank you. And a pleasure as well Mikalaa. And I very much appreciate your time and asking me to be involved in this.

Mikalaa Martin [00:39:17] If you enjoyed today's episode, be sure to like and follow Just Science on your platform of choice. For more information on today's topic and resources in the forensics field, visit forensicCOE.org. I'm Mikalaa Martin and this has been another episode of Just Science.

Introduction [00:39:36] Next week, Just Science sits down with Dr. Michael Nirenberg to discuss the forensic subdiscipline of forensic podiatry and a variety of cases that he is supported through performing gait analysis and utilizing footprint impression evidence.
Opinions or points of views expressed in this podcast represent a consensus of the authors and do not necessarily represent the official position or policies of its funding.
 

Introduction [00:00:01] RTI International's Justice Practice Area presents Just Science.
Introduction [00:00:09] Welcome to Just Science, a podcast for justice professionals and anyone interested in learning more about forensic science, innovative technology, current research and actionable strategies to improve the criminal justice system. In episode seven of our case Study season Just Science sat down with Ross Krewenka product manager IDEMIA and Mike Ransom, automated print manager for the Michigan State Police, to discuss the development and use cases of contactless fingerprint capture technology. Traditionally, ink and paper are used to capture fingerprints from subjects.
However, advances in technology have made it possible to document fingerprints electronically. Furthermore, technological advancements have made it possible to capture fingerprints without subjects physically encountering fingerprint sensors or being touched by law enforcement. Listen along as Ross and Mike describe the process of adapting industry fingerprint technology to the public safety field. How contactless fingerprint capture technology can benefit individuals with special needs and preferences and the impact of this technology on the future of identification. This episode is funded by the National Institute of Justice's Forensic Technology Center of Excellence. Some content in this podcast may be considered sensitive and may evoke emotional responses or may not be appropriate for younger audiences. Here's your host, Jaclynn McKay.
Jaclynn McKay [00:01:21] Hello and welcome to Just Science. I'm your host, Jaclynn McKay, with the Forensic Technology Center of Excellence, a program of the National Institute of Justice. On today's episode, we will discuss contactless fingerprint capture technologies. Here to guide us in this discussion is Mobile Solutions product Manager Ross Krewenka and automated print manager Michael Ransom. Welcome, Ross and Michael. Thank you for talking with us today.
Mike Ransom [00:01:47] Thanks for having us.
Ross Krewenka[00:01:47] Yeah, thank you.
Jaclynn McKay [00:01:48] Ross, I'm going to direct the first question to you. Can you provide a little information about your background and how you became involved with mobile technologies?
Ross Krewenka[00:01:56] Sure. So I'm a product manager with IDEMIA and primarily my job focus is on solutions for officers in the field to help identify people when when they don't have ID or they can't provide their names. So I have a background building applications and working with mobile devices and, you know, really kind of focused on that for the last few years at IDEMIA and contactless fingerprints really plays into that.
Jaclynn McKay [00:02:23] Mike, can you describe your background and how you came to supervise the automated technologies at Michigan State Police?
Mike Ransom [00:02:29] Yeah. So before I was the automated manager, I actually did a lot of computer programing. And some SQL report programing. So after a bit I thought that there was a nice fit. And so I've been working with fingerprints for about nine years now.
Jaclynn McKay [00:02:44] Nice. Well, Ross, technology is always advancing, and now it's possible to capture fingerprints without having to come into contact with subjects like traditional fingerprint sensors. Can you describe how this technology actually works?

Ross Krewenka[00:02:58] So, I mean, really, the big difference between contact fingerprint capture and contact lists. Obviously, we have to deal with the distortion that's caused on a physical contact fingerprint. But really the how the technology advances with a lot of contactless solutions is we're actually taking a high rate video feed of your fingers or while they pass through a device or if you put them in front of a phone and then the technology is advanced to the point where you can look at the individual frames and pick out those that capture the fingerprint and refine them so that they could be used for for search. So really, the technology is is kind of moved from a actual touch contact to a video stream of fingers. And like I said, the technologies is advanced enough to where you can just pick out the frame of the best image.
Jaclynn McKay [00:03:51] Could you expand on what kind of contactless fingerprint capture technologies are available and what type of cases they support?
Ross Krewenka[00:03:58] Sure. Yeah. The contact tech fingerprints have actually been around for quite some time. Some of the earlier products were available on the market almost about ten years ago, so we just haven't really heard of them and they just haven't had a lot of adoption. But the earliest devices for contactless were were physical devices that usually included, you know, up to four different cameras inside the device that's pointing at a subject's fingers at different angles as they either pass through the device or put their hands in the device. A lot of these devices early on were used for access management. So you just typical access into office buildings, that kind of thing. That technology has been available for a little bit in the private sector and now we're seeing advancements with, you know, mobile devices and essentially having, you know, a product that you don't even need extra hardware for. You can just leverage your phone to do that. But yeah, there have been some early, early advancements in physical devices that you'll see out there. And I think as contactless becomes more popular, some of those kind of stationary devices with multiple cameras will be more popular in the industry for sure.

Jaclynn McKay [00:05:06] What about the strengths and. Possible limitations of this technology. Can you talk about that?
Ross Krewenka[00:05:12] Sure. Yeah, no, no problem. You know, with contactless, you know, first and foremost, you know, your software has to be able to deal with the distortion of a fingerprint. So when you take a traditional fingerprint, you know, you're usually pressing down on a plate and or a piece of glass, and it's spreading out your fingerprints a little bit when you do that. So when you take a contactless fingerprint, it's just an image.
There's no compression on the finger. So the matching algorithms have to take that into account when they're trying to match contactless fingerprints against contact prints. You know, so there's an adjustment to the algorithm matching that will need to occur in order to actually match as far as, you know, some of the limitations of contactless. You know, it really does perform a lot better than than contact devices. When you talk about dirtiness on the fingers or wet fingers or even the different environmental conditions. But you do have to be, you know, depending on what type of capture device you're using, you have to be mindful of the scenario you're trying to capture fingers in. If you don't have you trying to do it with a phone, you have to be mindful of the background and kind of some other things that are going on, because sometimes it is difficult to actually identify which fingers you're trying to get captured, especially when you're using a phone. So, you know, there's not a lot of drawbacks to contactless. And I think that's why we feel like in the future this is going to replace contact fingerprints. Right now, I think there's maybe some fringe cases that are still being worked out, but for the most part, not a lot of drawbacks to the actual contactless.

Jaclynn McKay [00:06:49] So I know proper technique for taking a ten print card is to pretty much roll from the edge of the fingernail to the other edge of the fingernail. And obviously, you know, fingers are rounded. So with the contactless, how can you get that entire area of the friction rich skin?
Ross Krewenka[00:07:09] Yep. Yeah. So we're you know, one of the things you're trying to really get is from nail to nail on all the fingers. So I'll talk about two different capture devices. Again, they some of the earlier contactless devices that have been developed that have stationary cameras within the device, they're actually pointing at the finger at different angles. And because of that, you can get a really wide fingerprint that pretty much goes from nail to nail. You can actually get the sides of it with an actual mobile phone. You don't have the advantage of having multiple cameras. So you do have one that's looking directly on to the fingers. So you do miss some of that edge. However, the technology is advancing to the point where I know that we're looking at solutions that could possibly where you move your device in order to get the rest of the finger. Some of the newer phones come equipped with a LIDAR technology that can be leveraged to get a better picture. So we're constantly looking for ways to improve the the use case on the mobile phone. But for some of the physical devices that exist today that do contactless, the camera positioning actually allows you to get nail to nail.
Jaclynn McKay [00:08:17] Mike, I'm going to toss this next question to you. Can you discuss how this technology has been implemented in your agency?
Mike Ransom [00:08:23] Sure. Michigan State's actually been using mobile I.D. technology for over ten years. And even prior from when I got the position back in the day, we were using the old technology with BlackBerry phones. That kind of tells you how far we go back. But going forward, contact technology has improved and improved. And so we were very happy with our contact technology and we're using it really well in Michigan and using it quite a lot. After a while, my division director had come in and said, Hey, you know, let's supplement a little bit this contact technology with contactless. And he's you know, a lot of it was due to the there's a lot of upfront costs and equipment stuff for the contact technology. So at the time it was it was hitting a rate about 75%. And me, myself, I always thought if someone says it's a hit, I want it to be hit. I don't want to be 75%. And I don't want people thinking that it's, you know. And but he said, well, it's better than nothing. And so since he was the division director, I said, okay. Yes, sir. So we moved forward and we started looking at different vendors for contactless. And once you put the word out there that you're going to something, the vendors are going to come out of the woodwork. And really there was nobody who had a good solution. We actually had people coming with Styrofoam boxes saying this is what would be if we had one, you know? So we decided to approach IDEMIA. And because they had done had been doing the morpho way for a long time, which is a another contact solution, and we weren't really impressed with what they had. And after a while, as technology got better, we started investing a little more. And then we started working with them and we've worked with them for like 3 or 4 years to take a solution that was going to be a proof of concept and actually turn it into a real solution. And right now in the field, we're really in a testing phase because the FBI has not officially approved it to hit their databases. So we can't what we call officially it in Michigan. But we do have some of the fields that are working on their testing in a pilot phase along with the contact technology and the reviews are positive.

Jaclynn McKay [00:10:14] That's really exciting that the technology has been overwhelmingly positive. Could you discuss kind of what sort of case examples that this would be used in?

Mike Ransom [00:10:24] So we have a few. Contactless is very strong. A lot of the in the field the officers I did not know this when we started doing mobile ID but they fingerprint the individual when they're in handcuffs and where the contactless technology where the screen is actually facing you when you're taking the photos, it actually is a huge advantage to the contact technology where they can't see the fingerprint quality or they can't see how they're taking it. Also, another use case that I'm pretty excited about is I get to champion the special needs and have programs for that, fingerprinting them, and for hypersensitive kids who don't like to be touched at all, we can actually identify them without physically going hands on and which will limit the trauma to them greatly if we find them in the field.

Jaclynn McKay [00:11:05] So in thinking about the future, how would you like to see this technology expand? And then are there any other areas that might still need improvement?
Mike Ransom [00:11:14] Yeah, so I see a bright future for contactless. Currently we about a year ago we tested it against contactless in a control environment and really we're getting a 97% hit rate contact list versus a 99% hit rate for contacts. So I can definitely see it going forward and be the way of the future. I know a lot of officers are very concerned about residue on patterns and, you know, drugs and stuff and dirt and and so it's one of those things where I think they're going to enjoy it once it goes full screen. There are advantages and disadvantages, like any technology. So like I said, we can have other use cases where we can use contacts a little better, but the learning curve is a little higher. So like Ross alluded to earlier, sometimes the phone is trying to focus on the background or sometimes. And so that's kind of one of the challenges we're going to have as far as teaching them. But I do see this the future. And as technology increases, I mean, we may even be able to do things at more of a distance and such like that. So I can see it being a great thing.
Jaclynn McKay [00:12:11] Ross do you have anything else to add?
Ross Krewenka[00:12:12] Yeah, I think from an industry perspective, you know, kind of the way we're looking at it as it erythema is, you know, first step is to establish contactless is as the standard for criminal searches for law enforcement. Right. You know, in those situations, you're taking fingerprints from an individual, you're not enrolling them. You're simply trying to search against a database. Right. So we want to establish contact devices and law enforcement and make sure that that use case is something that we pursue. I think that the next step after that is to really take a long, hard look at at enrollment and contactless enrollment. Right? So this is replacing your your traditional live scans or other enrollment devices with contactless devices. And like Mike said, you know, the technology is moving that direction. And I'm sure there'll be advancements before everything is said and done. But yeah, from a from a logical perspective, I think, you know, we really want to establish contactless as as the way to to search. And then, you know, soon after that, you know look at ways how we can start taking fingerprints for enrollments in a in a contactless way.

Jaclynn McKay [00:13:18] So, Mike, you mentioned that this technique can be used in the field to take fingerprints of individuals that are in handcuffs so officers on the street can use this technique. Can you explain a little bit about how they would be trained and what all that would entail?
Mike Ransom [00:13:36] So technology nowadays is usually pretty self-explanatory. I mean, the application walks them through the steps step by step. It's not very difficult training, really. I could talk to an officer for five minutes. They would be up and running. The biggest problem now is a better photographer is going to be a better fingerprint taker

so that the folks it's all about the camera focus and such. And with the newer technologies and newer phones, even, that's been eliminated a little bit more. And so it's really almost out of the box. You can use it. It's not a lot of training needed.
Jaclynn McKay [00:14:05] Ross So anything you want to add?
Ross Krewenka[00:14:07] Yeah. With so IDEMIA's mobile biometric check application. The mobile application, or really, it's designed in a way that is very intuitive and we're not really asking for the officer to do a lot to actually get fingerprints. You know, officer safety is key. We understand, you know, during the traffic stop, officers are paying attention to a lot of different things, you know, So we tried to make the application as easy as, you know, putting your hand in front of the phone and holding it there for a second and getting fingerprints. Right. So that training really the only part that becomes a little bit of a training issue is just how far do you keep the phone away from a subject's hand? Every phone manufacturer, the the actual camera in the phone. It tends to have a different focal point even across iOS phones and Android phones. So as someone taking the fingerprints, you know, finding that distance away from the device that takes the best fingers is a little bit of a training issue where we do have indicators and. Inside the application that help you get the right distance. But yeah, if it's the first time doing it, usually you have to show someone this is about where you go and typically after someone takes their prints a few times, you know, it's a non issue. They could just move forward with the technology.
Jaclynn McKay [00:15:22] Thank you for bringing up how important this is to officer safety because I think that this technique can really fill a void there. Mike, you also mentioned that this technique is beneficial to individuals with special needs. Can you tell us a little bit more about that program?
Mike Ransom [00:15:38] I mean, you've probably all heard about a person maybe who've wandered away from a retirement home or person with special needs, maybe autism found in the street. And it's difficult finding where they, you know, they live. So we in Michigan have passed a law that basically stating we as parents or guardians of special needs kids or a guardians of elderly members with dementia, whatever, we can allow them to fingerprint stored in that database along with a photo. And we can use fingerprints and facial recognition both on the street to be able to identify them and immediately alert the officer if they're ever in contact with them, that this person's special needs and they may not be able to respond to directives. Special needs sometimes does mirror like unfortunately, someone with high drug use or strung out on drugs or on alcohol. And so there's a different way we respond to those people who are maybe having issues with substance and those that have special needs. There's a different voice. We use different demeanor. And if we can get these responses back and usually within 50s, these responses come back from the mobile ID, we can figure out who we're dealing with and really understand.
Jaclynn McKay [00:16:41] Thank you for discussing that. Ross, Can you discuss what some of the challenges are for law enforcement when it comes to implementing this technology?
Ross Krewenka[00:16:48] Yeah, that's that's a great question. You know, one of the biggest challenges I think, facing law enforcement today is the actual just use of mobile devices. A lot of agencies, you know, they already budget for having cell connectivity in the patrol cars. You know, some haven't budgeted to actually provide devices to to their officers. And under no conditions would we ever expect an officer to utilize this type of technology on their personal phone for a number of different reasons. So for those agencies that are looking to leverage this technology, it's it's really important, first off, to

have a mobile device management system in place to be able to manage your fleet of mobile devices. Essentially, this is going to give you control. So whether an officer loses a phone or it gets stolen, you can it you can wipe it or clean it from a remote location. So these are kind of just best practices that that agencies need to kind of look at and implement before they can really start leveraging some of the apps on the phone. Again, you know, under no condition would we ever want someone using their personal device to do this kind of thing. So that's been a little bit of a challenge. We are talking to some agencies, but, you know, as time goes on, you're going to see more and more officers get department issued phones, which is really going to open up their ability to use a lot of cool tools in the field like like contactless technology apps.
Jaclynn McKay [00:18:07] Mike, can you talk about some of the implementation challenges your agency faced and what the future of implementation looks like at your agency?
Mike Ransom [00:18:16] With new technology, there's there's always especially a little resistance for more the older generation, but the younger generations are pretty much demanding nowadays. So the a lot of the resistance we had is going from something that's familiar to something new. People know that that's that needs to happen. So they're they're coming around. But it's it's a selling tool and we want it to be perfect as we push it out to the field. Because once that first impression comes, if it's not a good one, you know, they have a tendency to be less likely to use it. What's really stopping us to go from full implementation right now is the FBI still needs to test to make sure that it is okay to hit their database, were not approved to hit the FBI database. As of now, we can hit our Michigan database. So anybody who, you know, commits a crime in Wisconsin or a different state, we won't know that on a mobile ID hit right now with contactless. So we're looking to start testing with them later in the year and hopefully be done with that and get approved pretty quickly. I guess one of the other roadblocks in getting this technology is funding and really with as many things as this can help. So you're talking about public safety. You talk about officer safety, you talk about special needs. You can really plug into a lot of grants. There's a lot of grants out there. One of the times we advanced our contact technology, we got a quite a sizable grant to be able to buy new equipment to actually do that. So there are grants out there that you can plug into. You just have to look for them.

Jaclynn McKay [00:19:37] You brought up that because you haven't been able to fully implement this technology and you can only search the prints in Michigan. Are you also taking the traditional type of prints in addition to the contactless prints of individuals?
Mike Ransom [00:19:53] So as far as enrollment, we are still only using contact prints and we will probably the foreseeable future for the queries. We are doing them side by side right now. So we are doing the contact with the contact prints once the FBI. Comes along and is able to approve it. Then we will allow the contactless to be operated in Michigan.
There has been discussions to allow the contactless to be approved in Michigan without the FBI to. So it does limit us to the Michigan database and any crimes in Michigan. But sometimes that the thought processes is something is better than nothing. So we're in discussion of that right now.
Jaclynn McKay [00:20:29] Ross, is this technology being used anywhere outside of Michigan?
Ross Krewenka[00:20:33] Yeah, actually, that's a great question. So IDEMIA has been developing our mobile biometric check application for the last few years and working with with agencies like Michigan State. However, we have worked with a couple of other agencies to actually implement the same type of solution. Folks in Arizona Department of

Public Safety do have our mobile biometric check application and they are currently right now searching their own state database or their state AFIS system for fingerprints. And then we also have another customer in the northeast, part of the of the United States that's used the technology essentially for identification in a number of different use cases. So yeah, there we do have implementations again, that there is a tendency from some agencies to wait until we have the full FBI approval. Again, agencies in addition to just searching their state AFIS they really would like to search the risk database as well. So for those folks that have AFIS systems that are at the state level that suffice for what they're doing, it's a great opportunity to implement the technology today.

Jaclynn McKay [00:21:38] And so from a disaster victim identification or an unidentified human remains standpoint, could this technology be used to help identify deceased individuals?
Ross Krewenka[00:21:49] Yeah, that's that's a great question. And we hear that a lot. A lot of times, you know, identifying someone out in the field becomes really important. And if that person is not respondents or unfortunately has deceased, really you're reliant on the fingerprint images to kind of find out who that person is from a purely, you know, deceased type of individual. There is going to be a breakdown of the fingerprint over time and it will decompose over a certain amount of time. And and unfortunately, once once a body has gotten to that point, you won't be able to take fingerprints from it. But, you know, there's a certain amount of time after someone's been deceased where you can still use contactless technology to get the fingerprints in a similar way that you would a contact device. And yeah, there's a certain amount of time afterwards where that would work just fine to get their fingerprints.

Mike Ransom [00:22:39] And from a law enforcement perspective, that's probably one of the reasons I was most shocked that that mobile ID was used for was for deceased individuals and contactless and contact can pretty much pick up the same ridge structures about the same amount for the same time. We've had certain people report that they've been in the morgue for 4 or 5 days and they have no problem picking up their fingerprints.
Jaclynn McKay [00:23:02] So we've talked about using this technology on developing fingerprints from individuals. But on crime scenes, as we all know, you can develop latent prints. Could this technology be used in that capacity at all?
Ross Krewenka[00:23:19] Currently, the contactless technology, it's not at a point right now where you can just take your phone and take a picture of a latent fingerprint and send it through for search. Unfortunately, the cameras in normal smartphones today are just not equipped with the technology to to actually just get that image off of the various different surfaces that you might find a latent fingerprint. We have been experimenting with certain applications. We know that if you treat the fingerprints or you dust the fingerprint or put a fluorescent light on the fingerprint does usually make the image easier to capture. And and there is some possibility to kind of kind of use a phone in conjunction with some of your traditional methods to to get latent fingerprints. But unfortunately, it's not a technology right now that's that's kind of been developed to a point where it's it's easier for people to use and it's really going to provide a a time saving or benefit. Again, we think that moving forward, that's going to be extremely beneficial to crime scene investigators to to just use their phone to capture latents. But currently the technology is just just not there just yet.

Jaclynn McKay [00:24:30] Yeah, I think that's the dream, right, for crime scene investigators to be able to process and get those prints and search them right away and provide those leads to law enforcement as soon as possible.

Ross Krewenka[00:24:40] Yeah, of course. I couldn't agree with you more. And, you know, a lot of times in those those scenarios, time is of the essence, right? So the faster you can can get a latent prints in for search and the faster you can make an identification, you know, it's really going to provide a lot of value to the agencies that are working the case and actually, you know, getting the case solved as quickly as possible.
Jaclynn McKay [00:25:00] Ross and Mike, thank you for your time today discussing this topic with us. It has been a pleasure speaking with you.
Mike Ransom [00:25:07] Thank you so much.
Ross Krewenka[00:25:07] Thank you.
Jaclynn McKay [00:25:08] If you enjoyed today's episode, be sure to like and follow just science on your platform of choice. For more information on today's topic and resources in the forensics field, visit forensic coe.org. I'm Jaclynn McKay and this has been another episode of Just Science.
Introduction [00:25:27] Next week, Jason sits down with Brian McVicker to discuss processing fabric for footwear and tire impressions using the and ninhydrin. The points of views expressed in this podcast represent a consensus of the authors and do not necessarily represent the official position or policies of its funding.
 

Introduction [00:00:05] Now this is recording RTI International Center for Forensic Science Presents Just Science.

Voiceover [00:00:19] Welcome to Just Science, a podcast for justice professionals and anyone interested in learning more about forensic science, innovative technology, current research, and actionable strategies to improve the criminal justice system. In episode one of our Case Studies Part 1 mini season, Just Science sat down with Michael Fagert, a certified latent print examiner at the Kansas Bureau of Investigation, to discuss a latent print phenomenon that is not often seen in casework. There are very few instances of identifiable fingerprints on cartridge cases recovered from crime scenes, as the firing process introduces adverse physical and thermal stressors to fingerprint residues. Several processing methodologies have been investigated for the development of latent prints on spent ammunition like gun blue solutions, but only a few studies reported success on case work samples. Listen in as Michael discusses his published case report on how an untreated latent print encountered on a cartridge case was subsequently identified to the suspect in the case. This episode is funded by the National Institute of Justice's Forensic Technology Center of Excellence. Here is your host, Jaclynn McKay.

Jaclynn McKay [00:01:21] Hello and welcome to Just Science. I'm your host, Jaclynn McKay with the Forensic Technology Center of Excellence, a program of the National Institute of Justice. On today's episode, we will discuss a case study published in the Journal of Forensic Identification related to an identifiable fingerprint found on a cartridge case at a crime scene. Here to discuss this case is Michael Fagert. Welcome, Mike. Thank you for taking the time to talk with us today.
Michael Fagert [00:01:46] Thanks for being interested in this case study and allowing me to share with the audience.
Jaclynn McKay [00:01:51] Yeah, absolutely. Can you discuss your professional background a little bit and how you became involved with this case study?

Michael Fagert [00:01:57] I'm a certified latent print examiner with over seven and a half years of experience. I currently work at the Kansas Bureau of Investigation at their Forensic Science Center. I've been with the KBI for a little over a year now. Prior to that, I was at the Kansas City Missouri Crime Laboratory in their latent print section. I worked there for about six and a half years, and that's where I was employed at the time that this case came about.

Jaclynn McKay [00:02:22] Do you mind providing a little bit of background of the case for our listeners?

Michael Fagert [00:02:25] Yeah, so in December of 2019, the K.C.P.D. responded to the scene of a homicide where they found a victim in between two residences in a neighborhood. They secured the scene and they talked to some witnesses. The witnesses indicated that they heard some gunshots and then they observed a male leaving the scene in a black hoodie and black pants. And so while the officers were holding the scene, they noticed an individual at a nearby residents that matched those descriptions. So they took that individual into custody for further investigation. At the same time, our CSI technicians responded to the scene to process that scene. Part of their scene processing they collected four cartridge cases, one being near the victim's body, one near the door to the

victim's residence, one near the driveway and one near a nearby street. This is the evidence that was then collected and brought back to the lab and submitted for us for examination.

Jaclynn McKay [00:03:27] So based on the evidence that was collected in this case, was there anything interesting about it?
Michael Fagert [00:03:31] The crime scene technician who responded to the scene, she was notorious for always reviewing her photos when she got back to the lab to see, am I capturing everything in focus? Is there anything that you could do better going forward? And one thing that she noticed while reviewing her photographs was a visible latent print on one of the cartridge cases that happened to be the one near the street. But this cartridge case had already been swabbed on the scene by the crime scene technician. So she brought those photographs to our latent print supervisor, and he thought it was something that we could definitely look into and do some more work. And so he brought it back to the examiners in our section and looked to see if somebody was able to work on it. Fortunately for me, I wasn't in the middle of anything and thought it was super interesting, so I volunteered to work the case.

Jaclynn McKay [00:04:20] So after the cartridge case was swabbed, could you guys still find a print on the cartridge case?

Michael Fagert [00:04:26] Yes. So kind of how it worked was I got these crime scene photographs and I analyzed the photograph of the cartridge at the scene and was able to determine that that print was of value and was able to compare it to a suspect and identify that suspect. But still interested to see if there was anything remaining on the cartridge case or anything that still remained there, so I was able to request that evidence from our firearms section and that impression was actually still intact on the cartridge case.

Jaclynn McKay [00:04:58] Previously, I worked as a crime scene investigator for several years, and I don't ever recall getting latent print impressions of value on cartridge cases. This instance is quite unique. So as luck would have it, the crime scene photograph actually depicted the latent print, and as we know, the fingerprint probably didn't go all the way around the cartridge case so had the fingerprint not shown up in the photo, this case may have never happened. Does that sound accurate?
Michael Fagert [00:05:24] Yeah. If the crime scene technician didn't review her photos, this is some evidence that we could have missed. And it would be kind of a missed opportunity for me to do some investigation and a missed opportunity to present this to a community of instances in which fingerprints might persist through the firing process.

Jaclynn McKay [00:05:42] Not only is this very rare, it seems like we got lucky in this case.

Michael Fagert [00:05:47] For sure.

Jaclynn McKay [00:05:48] So what made you want to pursue research into figuring out how this print lasted on the cartridge case through the firing process?
Michael Fagert [00:05:56] It was definitely a very rare occurrence. We hear in the field and we've - studies have shown that the firing process of a firearm exerts physical and thermal stressors on any latent impressions that could be on those cartridge cases. So it's

not something that happens very often and something that is very interesting to me, and I have been fortunate enough to do some research while that were able to find that impression still intact on that casing, I thought it would be very beneficial to find out how this happened and then also share with the community because it is such a rare occurrence.

Jaclynn McKay [00:06:31] Can you talk through a little bit more about the trace analysis that was done?
Michael Fagert [00:06:36] So originally I thought that this impression could have been etched into the metal of the cartridge case. I've read about the interactions of fingerprint residue having a corrosive nature on cartridge cases, creating an etched impression. So to test that, I took the end of a DNA swab and just lightly scraped along the edge of the impression and this really easily removed that residue, confirming that it wasn't etched.
These nickel plated and nickel composition cartridge cases are corrosion resistant so that explains why the residue is easily removed. So at that point, I took the cartridge case over to the trace evidence section where they collected a scraping of the latent residue that they could run some additional tests on. And so they did an FTIR analysis, which is the Fourier transform infrared spectroscopy, and they also did micro X-ray fluorescence to look at any potential inorganic components that were present in a pyrolysis gas chromatography-mass spectrometry analysis for any organic components of the residue.
Jaclynn McKay [00:07:49] And were there any major findings from those trace analysis?

Michael Fagert [00:07:53] I think there were some significant findings that could indicate what the residue potentially was. The X-ray fluorescence, it didn't reveal any foreign inorganic materials, so no additional inorganic materials were present. The paralysis analysis, the results were too minimal to cross the threshold, so they weren't able to make any definitive analysis of what those components could be. But the FTIR analysis is what provided the most informative information that was present with the spectra that were generated from the FTIER samples of the scraping, the key peaks of the spectra were highlighted by the Trace Examiner, and I compare those peak numbers to a table that I found of known eccrine and sebaceous deposits, so what peaks they have in their spectra, and found a great deal of correspondence between this scraping from the cartridge case and those in that table. So while these components aren't exclusive to fingerprint residues, it is an indication that this very well could have been just natural fingerprint residue that survived through the firing process.

Jaclynn McKay [00:09:08] Okay. So you talked about your theories behind whether the fingerprint was etched into the casing and then you talked about all the trace analysis that was involved with determining whether this was a normal eccrine or sebaceous fingerprint on the casing. Can you maybe talk about some of the other theories that you had as far as ruling out whether anyone had touched the casing after it was fired?

Michael Fagert [00:09:35] Yeah, so there's a potential the something this clear and well- defined could have been deposited post firing. Mentioned the witness statements about observing someone leaving the scene after the gunshots were heard and looking into the reports filed by the officers. These witnesses were in their houses at the time of hearing the shots being fired. So there was a small window of time in which it would take for them to either look out the window or come outside in which that casing could have been handled. We don't know because we weren't there at the time, unfortunately. But it seems odd that somebody might try to pick up just one casing as they're leaving, but there's

definitely a possibility it could have been handled. So it's something that we can't rule out definitively as an option.
Jaclynn McKay [00:10:23] I think your research is very valuable to the field, but I also find it interesting that you were able to do research at a publicly funded laboratory. Can you talk a little bit more about how you had the capability to do that and how supportive your laboratory management was of that?
Michael Fagert [00:10:40] Sure. I consider myself incredibly fortunate that so much additional work was able to be conducted on this case. Once that print was identified and I found that it still persisted on that cartridge case, I wanted to know more about how it happened and how it persisted. Was this some sort of foreign material that was present, that was better suited to survive the foreign conditions? Was it something that became etched into the cartridge case or is it just standard fingerprint residue? So I approached our lab director at the time, who was previously the trace evidence supervisor, brought it to his attention, I said, hey, I would like to look into this some more, is there anything you think we can do? And very fortunately he thought it was a great example of something we could look further into. We got with the chemistry supervisor as well to determine what could be the best path to pursue. And we thought that the trace evidence section would have multiple tests that we could run on it and potentially be able to determine what comprised that residue on the cartridge case. And then we're also able to run the DNA swab that was collected as well.

Jaclynn McKay [00:11:52] And when you wrote this case report, you did a literature review. Were you able to find any publications that pertain to identifiable prints found on casings in casework?

Michael Fagert [00:12:04] So I was able to find a few publications involving casework samples. The vast majority of what I encountered were tests on different development techniques and what would work best on groomed samples in the laboratory. But there were only three articles that I found specifically with case work examples. One of those was from a Minneapolis lab where they looked at, I believe it was about 259 casings, and they did find one print of value, but they attributed this to being deposited post-firing. A Denver lab reviewed some cartridge cases over, I believe, a two-year period in which they didn't find any fingerprints of value on those spent casings and then there was a Northern Ireland study where they looked at all the casing submitted from homicides over a two year stretch. And they didn't indicate the number of cartridge cases that they looked at or examined during that time period, but they did find two fingerprints of value. One of those was inadvertently deposited by crime scene personnel during the collection, or post firing phase, and the other one was not identified. So one potential instance where a fingerprint could have been left prior to the firing process in these case work examples.
Jaclynn McKay [00:13:27] So you mentioned that through the use of the crime scene photographs, you were able to find a print still on a cartridge case that had been swabbed and screened for NIBIN entry and when you retrieved the cartridge case for latent print analysis, you saw that the prints still existed on the cartridge case as well. Can you talk a little bit about how you used the photograph and the cartridge case during your latent print analysis and what your results were from that?

Michael Fagert [00:13:58] Yah, so the first thing I did was I received the crime scene photograph and there were some interesting limitations with this. Obviously it was a documentation photograph, so it's from further away, has less resolution when you

zoomed in on the image itself. So there's a little bit of pixelation. And the cartridge case wasn't parallel to the film plane, so it's just lying naturally there on the ground. And so there's some little bit of perspective that was off, but just working with that image and doing a little bit of digital enhancements to help us contrast in Photoshop, there was enough information present there in that latent in the crime scene photo to be able to compare it to the known prints of the suspect. And I was able to identify that impression. After retrieving the cartridge case itself from the firearm section, the latent print was observed in its totality. It didn't look like it was altered or changed from the crime scene photos, which means that area was probably just missed during the swabbing process because it wasn't etched into the cartridge casing or anything. And so additional laboratory photos were taken just to have more exam quality photos of that impression. I looked at it, compared it to the crime scene photo, and it was the same rich detail again. And then also compare that laboratory photo then again to the suspect and was able to identify as well.

Jaclynn McKay [00:15:25] And did the case gain any information from DNA results on the swabbing of the casing?
Michael Fagert [00:15:30] A DNA analyst did run quantification step on the swab taken and they found 0.02 nanograms of human DNA from the swab, 0.01 nanograms being male DNA. And in speaking with the DNA supervisor, she indicated that this was a typical amount of DNA that they would encounter on spent casings, and in this instance, it wouldn't be enough DNA to proceed on to the amplification stage and further on down the line.
Jaclynn McKay [00:16:00] So as a result of this, had any procedural modifications taken place?
Michael Fagert [00:16:06] Prior to me starting at the Kansas City, Missouri crime lab, the latent print section conducted an internal review of firearms evidence, and they looked at their success rate of getting usable fingerprints off of live rounds and spent casings and firearms and they found with the live rounds that they had a 1% success rate in finding any fingerprint detail that was of value for the section. And they determined that that was very low success rate for the sheer quantity of that type of evidence we were receiving so that we wouldn't be conducting any latent print processing of live rounds and spent casings unless there were special circumstances in which it needed done. Then leading up to this case that we encountered, there was an increase or a lot of gun related crimes in the Kansas City area, so the lab was looking into, was there anything more we could be doing to maximize the evidentiary value of this firearms evidence? And so our latent print section was looking into methods such as vacuum metal deposition or using a gun blue solution to process those cartridge cases and DNA was running tests to see how frequently they could get usable genetic profiles. And we found in the latent print session that this modified gun blue solution gave us the best results. But the DNA section was still having significantly higher rates of getting usable profiles than us. So we were prioritizing DNA over latent processing because that processing of ours also was detrimental to DNA, the gun blue solution. So DNA was prioritized for those cartridge cases up until this spent casing was encountered. Once it was encountered, there was just a small modification that was made and those crime scene technicians were now conducting a visual examination of spent cartridge cases at crime scenes prior to swabbing. So that way, if they encountered a very large area of rich detail or something that stood out, it could be directed to the latent print section first, and we could try to find either nondestructive ways to photograph or develop that or work with DNA on how to best proceed with those ones going forward.

Jaclynn McKay [00:18:32] So you would say that your study still supports DNA analysis as the prevailing methodology for evidence collection on cartridge cases?

Michael Fagert [00:18:41] I would say so, yes. We worked through our submissions system and found that almost 3200 casings in shot shells were submitted by crime scene over a one-year time period, and aside from the casing observed in this case, only two additional casings were submitted in which there was a significant amount of rich detail present. So it was just something that says, hey, if you consider this here, and it's valuable to do a visual examination, but there's still going to be greater value in prioritizing the DNA evidence.

Jaclynn McKay [00:19:17] Although this is a very small procedural modification, was there any pushback with the crime scene unit changing the way that they operated at all?
Michael Fagert [00:19:26] Not that I'm aware of. The latent supervisor at the time was a former crime scene supervisor. So I'm assuming I would - we would have heard if they were not a fan of it. I think the way it went fine was it doesn't take a lot of additional time. You're already having to pick them up and the swabbing process takes a little bit of time to do so, just putting a flashlight on something or looking at it in the light prior to the swabbing isn't super time intensive. So it was kind of an easy adjustment to make.
Jaclynn McKay [00:19:53] And at the Kansas City Police Department, the crime scene technicians were the ones that actually swabbed the cartridge cases prior to submission to the lab?

Michael Fagert [00:20:01] Yes, they would swab them on scene.
Jaclynn McKay [00:20:03] Since the publication of your case report, is there any additional testing you wish you could have done or any theories surrounding this case that you're still curious about?
Michael Fagert [00:20:12] I don't think there's any additional testing that I would have done. Fortunately, we were able to be pretty thorough with that residue. Just we're unfortunately limited by the quantity that was present. So that kind of limited our results just there a little bit. I would be interested to know for sure when the impression was deposited and my feeling is that it was before firing, but there is that window in which nobody was present to see if it was handled. So I would like to know for sure when in fact that impression was deposited.

Jaclynn McKay [00:20:44] So this case involved several different departments in your laboratory. We got crime scene trace, latent prints, DNA. How was the experience working with all these different departments and was the process of collaborating pretty seamless?

Michael Fagert [00:21:00] Yeah, I think it was - it went very smoothly. Obviously great job by crime scene, not just identifying and collecting the evidence, but reviewing and being willing to come forward and say, hey, here's something that I missed before I swabbed, putting on to us to be able to work it, and then also the lab director getting other sections involved. There's a very small trace evidence section, so casework can be very extensive for them. It can be short or long based on what's submitted, so the ability for them to work that into their rotation to find out more for something that I would be interested in on a personal level that could potentially benefit the field, I think that was amazing. I think it's

really great when different sections can communicate with each other and work so fully on a case like this.
Jaclynn McKay [00:21:45] Do you have any thoughts that you would like to leave our listeners with?

Michael Fagert [00:21:48] I would just say to always be open minded in looking at how you could improve or modify some of your procedures. There's always weird case examples that come up and modifications aren't always necessary, but being able to look into how you can tweak how you do something to better serve the customer down the line is always a great thing to be able to do.

Jaclynn McKay [00:22:09] Mike, it has been a pleasure discussing your case report today. Thank you for taking the time to chat with me about this interesting phenomenon.
Michael Fagert [00:22:16] Thanks for having me on and giving me the opportunity to talk a little bit more about this case.

Jaclynn McKay [00:22:20] If you enjoyed today's episode, be sure to like and follow Just Science on your platform of choice. For more information on today's topic and resources in the forensics field, visit ForensicCOE.org. I'm Jaclynn McKay and this has been another episode of Just Science.

Voiceover [00:22:38] Next week, Just Science sits down with Stacey Chepren to discuss a case involving trace and digital evidence that solved a pedestrian hit and run. Opinions or points of views expressed in this podcast represent a consensus of the authors and do not necessarily represent the official position or policies of its funding.