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Use of BackTrack for the Directional Analysis of Shotgun Pellet Patterns

NCJ Number
Journal of Forensic Identification Volume: 60 Issue: 3 Dated: May-June 2010 Pages: 280-290
Shannon McClorry; Andrew Kastelic
Date Published
May 2010
11 pages
This study discusses the use of the BackTrack program to determine the directional analysis of bloodstain patterns.
Forensic identification officers encounter shotgun pellet patterns at crime scenes, and it is sometimes beneficial to have knowledge of the location from where the firearms was discharged. Currently, bloodstain experts use a computer program called BackTrack to determine the origin of a bloodstain pattern. The investigation reported in this article revealed that the mathematical relationship employed by BackTrack to determine the angle of impact can be applied to impacts from a pellet gun into BIO-FOAM (one-sample t-test; n=102, p=0.057). However, it would not be feasible to utilize BackTrack to determine the origin of a shotgun pellet pattern, because the calculated muzzle-to-target distance was often an order of magnitude off of the known distance, and thus would not be reliable. 3 figures and 9 references (Published Abstract)