Forensic science is the application of sciences such as physics, chemistry, biology, computer science and engineering to matters of law. Forensic science can help investigators understand how blood spatter patterns occur (physics), learn the composition and source of evidence such as drugs and trace materials (chemistry) or determine the identity of an unknown suspect (biology).
Impression Evidence: Strengthening the Disciplines of Fingerprints, Firearms, Footwear, and Other Pattern and Impression Sciences Through Research
Forensic examinations involving specific forensic science disciplines are typically dependent upon qualitative analyses and expert interpretation of observed patterns based on a scientific foundation, rather than quantitative results. These disciplines include latent fingerprints, questioned documents, footwear, and other forms of impression and pattern evidence.
The definitions contained herein apply to terms as used in this document.
This program assists existing crime laboratories that conduct multidisciplinary forensic analysis, including DNA, to reduce the number of items awaiting analysis to ultimately solve crimes and thereby help to increase public safety in the United States.
NIJ hosts free, self-paced online courses that include videos and animations developed with funding from NIJ. You are free and encouraged to use these as a resources in your own classrooms or other work. We ask only that you acknowledge NIJ as the source.
The videos and animations below are arranged by the course in which they appear.
Brian Cerchiai discusses a NIJ-supported a study conducted by the Miami-Dade Police Department on the accuracy of fingerprint examiners. The study found that fingerprint examiners make extremely few errors. Even when examiners did not get an independent second opinion about their decisions, they were remarkably accurate. But when decisions were verified by an independent reviewers, examiners had a 0% false positive, or incorrect identification, rate and a 3% false negative, or missed identification, rate.