NCJ Number
221169
Journal
Evidence Technology Magazine Volume: 5 Issue: 6 Dated: November/December 2007 Pages: 12-15,45
Date Published
November 2007
Length
5 pages
Annotation
This article examines issues in the debate about whether photographic documentation should be a standard operating procedure for all firearm and toolmark examinations.
Abstract
The call to require photographic documentation is part of a recent trend throughout forensics, particularly in the pattern-matching disciplines such as firearm and tool mark comparisons. On the other hand, Robert J. Shem, a firearm and toolmark examiner with the Alaska Department of Public Safety's Scientific Crime Detection Laboratory believes that it is best to allow qualified examiners to make their own decisions on the issue of documentation. He argues that any changes in standard procedure should fit well into the examiner's workflow and must work in all cases. Regarding the latter issue, Shem argues that photographic documentation does not always provide an accurate representation of what the examiner is seeing. Theoretically, a photograph should illustrate striae on two different bullets and show where they do and do not match. Shem believes that this two-dimensional comparison of striae on a rounded bullet does not accurately portray the three-dimensional characteristics of bullets in a comparison. He notes that a complete analysis relies on the expert's human eye, which has a lot more range of detail in highlights and shadow than a camera. Shem is also concerned that the promotion of the two-dimensional counting of striae portrayed in photographs will result in a flawed comparison that ignores bullet feature not evident in a given photograph. Two leading organizations, the Association of Firearm and Tool Mark Examiners and the Scientific Working Group of Firearms and Toolmarks, advocate a comprehensive approach that allows the examiner to choose the best forms of documentation in each circumstance.