Empirical Study to Improve the Scientific Foundation of Forensic Firearm and Tool Mark Identification Utilizing Consecutively Manufactured Glock EBIS Barrels with the Same EBIS Pattern.

摘要

This research conducted an empirical study to evaluate the reproducibility and uniqueness of striations imparted by consecutively manufactured Glock Enhanced Bullet Identification System (EBIS) barrels with the same EBIS pattern, as well as to determine the error rate for the identification of same gun evidence. The foundation of firearm and tool mark identification is that each firearm/tool produces a signature of identification (striation/impression) that is unique to that firearm/tool, and through the examination of the individual striations/impressions, the signature can be positively identified to the firearm/tool that produced it. The National Academy of Sciences Report questioned the repeatability and uniqueness of striations/impressions left on fired evidence as well as the validity and error rate in firearms identification. The Miami-Dade Police Department has been researching/evaluating Glock barrels since 1994. The Glock EBIS barrel is a polygonally rifled barrel, which has a barcode-like pattern added during the manufacturing process. Consecutively manufactured EBIS barrels with the same EBIS pattern are significant to the study because these barrels will be manufactured with the same EBIS equipment/tools and exhibit a similar pattern. Even though these barrels are consecutively made, their signatures should still be different. Test sets were assembled which included test fired bullets as well as unknowns. Participants were trained firearm and tool mark examiners throughout the United States and internationally. This empirical study established an error rate of less than 1.2 percent