NCJ Number
233768
Journal
Identification Canada Volume: 28 Issue: 4 Dated: December 2005 Pages: 1-48
Date Published
December 2005
Length
48 pages
Annotation
This issue presents feature articles on the recovery of footwear impression evidence at crime scenes contaminated with chemical warfare agents, maintaining objectivity in interpreting fingerprint comparisons, and maintaining a record of the image enhancements associated with a particular set of fingerprints.
Abstract
One article examines how the presence of chemical warfare agents influences the ability of the forensic identification specialist in recovering latent footwear impression evidence when using common footwear enhancement techniques. Also considered are the effects on the performance of footwear enhancement techniques of exposure to vapor compared to liquid chemical warfare agents, as well as the application of decontamination agents before and after footwear enhancement. A second article presents a case study that illustrates several key elements of the forensic identification discipline. This includes the importance of following proper scientific protocols; continued learning; and the self-restraint to never jump to a conclusion, even when the available evidence is apparently straightforward and overwhelming. A third article describes the functions of computer software that facilitates complying with the following accepted principles of fingerprint image enhancement: the original image must always be maintained in an unaltered state; the image enhancement steps must be recorded; and the enhancement itself must be repeatable by a person of comparable skill. The software recommended for facilitating compliance with these principles consists of the new versions of Adobe Photoshop CS and CS2, which have built-in image tracking. The user turns on "tracking" within "preferences," and every change in the original impact is recorded in the metadata. The second stage in recording image enhancement and preserving the original image is to use adjustment layers to make enhancements, saving the image as a multi-layered Adobe Photoshop Document (PSD). The article presents a step-by-step description of these procedures using figures.