Assessing Methods to Enhance and Preserve Proteinaceous Impressions from the Skin of Decedents during the Early Stages of Decomposition while Examining Environmental Variations across Seasons

The constant substrate involved in physical altercations in the commission of violent crime is human skin. It is likely that blood impressions are left on the skin of living victims or decedents during these violent interactions. Yet, skin is one of the least studied substrates in the impression discipline. In some cases, impressions are clearly visible but, it is much more likely that they are latent and not readily visible.

There are cases in which the enhancement of blood impression evidence on human skin was possible, but it is not standard practice, especially when blood impressions are latent. While visible blood impressions are best enhanced in situ at the scene of the crime, most often these impressions on decedents are not enhanced until the body is moved to the medical facility for autopsy increasing the possibility of damage to the impression evidence from handling and/or moving the body. Skin is semi-porous, and is therefore a difficult substrate to enhance through chemical enhancement methods due to background staining, which leads to suboptimal visualization of the impressions.

In addition to the staining of skin, visualization of impression details may be obstructed by competing background patterns, such as dermal scales, hairs, wrinkles, and variations in skin tones. Two commonly used dye stains, Amido Black and Hungarian Red have been used to enhance blood impressions on human skin and a newer methods have also been used in preliminary studies to effectively lift and enhance blood impressions from decedent skin. To date, a comparative analysis between these methods has not been conducted.

In collaboration with the Forensic Research Outdoor Station at Northern Michigan University, this research project will assess the effectiveness of enhancing blood and semen impressions in situ on decedent skin through the early stages of decomposition during summer and winter months. Upon completion of the research, the Wayne County Medical Examiner's Office will field test the enhancement method to better recover impression-based evidence from decedents in medicolegal cases. The research and implementation of this project has the potential to increase the recovery of evidence from human skin associated with violent crimes.

Note: This project contains a research and/or development component, as defined in applicable law, and complies with Part 200 Uniform Requirements - 2 CFR 200.210(a)(14).

CA/NCF