The Science Behind Firearm and Tool Mark Examination

• NCJ Number: 247879
• Journal: NIJ Journal Issue: 274 Dated: 2014 Pages: 20-22
• Author(s): Nancy Ritter
• Date Published: October 2014
• Length: 3 pages
• Publication Series: NIJ Journal
• Grant Number(s): 2010-DN-BX-K269
• Agencies: NIJ
• Publication Type: Report (Study/Research)
• Award: Miami-Dade Repeatability and Uniqueness of Striations/Impressions in Bullets Fired in 10 Consecutively Manufactured Glock EBIS Barrels

Annotation

This study of the ballistic examinations of bullets fired from Glock gun barrels determined whether trained firearm and tool mark examiners studying bullets fired through consecutively manufactured Glock firearm barrels correctly identified the gun that fired the bullet, as well as whether an examiner's level of experience was influential in the correct identification of the gun that fired an examined bullet.

Abstract

The study found that the examiners correctly matched the spent bullet to the barrel that fired it 98.8 percent of the time. The study also found that examiners with less than 10 years of experience did not reach different conclusions than examiners with more than 10 years of experience. The study sent 150 test sets to 185 firearm and tool mark examiners in 41 States, the District of Columbia, and internationally. This sample was the largest ever used for this type of experiment. A member of the Department of Mathematics and Statistics at Florida International University analyzed the results. The National Institute of Justice (NIJ), which funded this study, is also funding two ongoing studies that could provide information on the scientific foundation of firearm and tool mark examination as a forensic investigative tool. These studies are briefly described.