NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Confocal Microscopy Analysis of Breech Face Marks on Fired Cartridge Cases from Ten Consecutively Manufactured Pistol Slides
Published
Author(s)
Xiaoyu Alan Zheng, Robert M. Thompson, Todd Weller
Abstract
Ten (10) pistol slides with consecutively manufactured breech faces, were obtained from Sturm, Ruger Co, Inc. A total of nine (9) test fires from each pistol, for a total of ninety (90) test fired cartridge cases, were compared using comparison microscopy. Additionally, the breech face marks on the cartridge cases were analyzed using confocal microscopy combined with three dimensional cross correlation analysis algorithms. There was no overlap of cross correlation scores between matching and non-matching test fires. This provides objective data that supports the theory that microscopic impression toolmarks produced on fired ammunition such as breech face toolmarks are reproducible and can be used to both distinguish and associate fired cartridge case evidence to particular firearms.
, X.
, Thompson, R.
and Weller, T.
(2012),
Confocal Microscopy Analysis of Breech Face Marks on Fired Cartridge Cases from Ten Consecutively Manufactured Pistol Slides, Journal of Forensic Sciences
(Accessed October 20, 2025)