U.S. flag

An official website of the United States government, Department of Justice.

Pattern evidence

Physical Characteristics of Spatter Stains on Textiles Compressed

December 2023

It is well-known that bloodstain pattern analysis (BPA) on textiles is difficult and subject to many errors or misinterpretations. In this webinar, we probe the reason for this and suggest useful information that a bloodstain pattern analyst may be able to extract from the observed bloodstains. The data set demonstrates the roles of drop volume and impact speed in bloodstain formation on textiles.

This webinar was hosted by the NIJ Forensic Technology Center of Excellence on December 12, 2023. 

U S National Footwear Database System Feasibility Study

February 2022

The FBI Laboratory conducted a comprehensive study known as the National Footwear Database Evaluation. The purpose of the study was to determine the feasibility of developing and implementing a national footwear database system to generate criminal intelligence for law enforcement and serve as a tool for forensic science researchers. This webinar will highlight the team's findings, conclusions, and recommendations. T

his webinar was hosted by the NIJ Forensic Technology Center of Excellence on February 15, 2022.

The Effect of Time on Rusted Firearm Identification

January 2022

Although iron-based metals are popular for making critical parts of firearms, they are susceptible to corrosion or rust. There is currently little research on how long a firearm can be left to rust before an identification is no longer possible. This project evaluates the effects of rust on the common working surfaces of Glock and Smith & Wesson Sigma firearms.