AFTE Store - An Empirical Study to Evaluate the Repeatability and Uniqueness of Striations/Impressions Imparted on Consecutively Manufactured Glock EBIS Gun Barrels

The inability to identify fired bullets to individual Glock pistols resulted in an in-depth study of Glock+s polygonal rifled barrels, which resulted in the manufacturing of the Miami Barrel. The Miami Barrel was designed with the intent to give the barrel a unique signature. Glock has marketed the Miami Barrel as the Enhanced Bullet Identification System (EBIS). These barrels present a significant advancement for the identification of polygonal rifled barrels. An examiner with knowledge of the machining methods, awareness of the possible subclass transfer and diminishing quality of these gross markings over time should still appropriately arrive at positive identifications and/or eliminations. The greater concern may be an examiner not familiar with these markings that relies on the gross characteristics alone for a positive identification. The Miami-Dade Police Department Crime Laboratory obtained 10 consecutively manufactured Glock EBIS Barrels to further explore the repeatability and uniqueness of striations/impressions, as well as the capability of identifying bullets fired through consecutively manufactured Glock EBIS Barrels. On a voluntary basis, 150 test sets were created and distributed to laboratories in forty-four states and nine countries. The test set was designed to determine an examiner+s ability to correctly identify bullets fired from 10 consecutively manufactured EBIS Barrels to test fired bullets fired from the same barrels. Additionally, this empirical study established an error rate of 0.4 percent.