Citation

Weller TJ, Zheng A, Thompson R, Tulleners F. J. Forensic Sci. 2012; 57(4): 912-917.

Affiliation

Oakland Police Department, 455 7th Street, Room 608, Oakland, CA 94607. University of California, Davis Campus, 1333 Research Park Drive, Davis, CA 95618. National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, MD 20899.

Copyright

(Copyright © 2012, American Society for Testing and Materials, Publisher John Wiley and Sons)

DOI

10.1111/j.1556-4029.2012.02072.x

PMID

22390540

Abstract

Recent publications from the National Academy of Sciences have called for additional foundational research in the field of firearm and toolmark analysis. We examined test fires from 10 pistol slides with consecutively manufactured breech faces. A total of nine test fires from each pistol slide, for a total of 90 test fired cartridge cases, were compared using confocal microscopy combined with three-dimensional cross-correlation analysis algorithms. A total of 8010 comparisons were performed (720 matches and 7290 nonmatches). The average score for matches was 0.82 with a standard deviation of 0.06. The average score for nonmatches was 0.20 with a standard deviation of 0.03. Additionally, subclass toolmarks were observed on the breech faces, but the presence of subclass was not detected in the correlation analysis. There was no overlap of scores between matching and nonmatching test fires. This provides objective data that support the AFTE (Association of Firearms and Tool Mark Examiners) theory of identification.

Language: en