Applying 3D measurements and computer matching algorithms to two firearm examination proficiency tests

Published

January 8, 2017

Author(s)

Daniel B. Ott, Robert M. Thompson, Jun-Feng Song

Abstract

In order for a crime laboratory to assess a firearms examiner's training, skills, experience, and aptitude, it is necessary for the examiner to participate in proficiency testing. As computer algorithms for comparisons of pattern evidence become more prevalent, it is of interest to test algorithm performance as well using these same proficiency examinations. This paper demonstrates the use of the Congruent Matching Cell algorithm to compare 3D topography measurements of breech face impressions and firing pin impressions from a previously distributed firearms proficiency test. In addition, the algorithm is used to analyze the distribution of comparisons from a collection of cartridge cases used to construct a recent set of proficiency tests. These results are provided along with visualizations that help to relate the features used in optical comparisons by examiners to the features used by computer comparison algorithms.

Citation

Forensic Science International

Volume

271

Pub Type

Journals

Download Paper

https://doi.org/10.1016/j.forsciint.2016.12.014

Local Download

Keywords

Firearm and tool mark identification, Pattern matching, CMC method

Citation

Ott, D. , Thompson, R. and Song, J. (2017), Applying 3D measurements and computer matching algorithms to two firearm examination proficiency tests, Forensic Science International, [online], https://doi.org/10.1016/j.forsciint.2016.12.014, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=921661 (Accessed October 17, 2025)