NCJ Number
222968
Journal
Law Enforcement Technology Volume: 35 Issue: 4 Dated: April 2008 Pages: 84-88,90
Date Published
April 2008
Length
6 pages
Annotation
This article reports on tests of the AccuTrans Auto Mix Dispensing System ("AccuTrans"), which uses the new material polycinylsioxane, in lifting impressions of latent fingerprints and toolmarks from various surfaces.
Abstract
The testers found two primary benefits of AccuTrans use: ease of mixing and ease of application. The accuracy of detail and the availability of colors (white, brown, and transparent) also favor its use. The only negative finding was that brown AccuTrans had visible voids, cracks, and air bubbles when applied for casting, which might require the investigator to perform multiple castings. When tested with rough surfaces, AccuTrans yielded useable latent fingerprint impressions on all substrates but concrete block. The product's drying time was approximately 3 minutes at 78 degrees F. Back-light photography may be required if the AccuTrans becomes too thick for AFIS (Automated Fingerprint Identification System) entry or comparison. AccuTrans yielded positive results in lifting latent fingerprints from all of the smooth surfaces tested. As with rough surfaces, back-light photography may be needed if the AccuTrans becomes too thick for AFIS entry or comparison. This report describes the procedures and conditions under which the AccuTrans yielded positive results for fingerprint impressions on human skin, dry blood, and the fingers and palms of deceased persons. In the toolmark tests, brown AccuTrans was used to recover several tool impressions in wood. The tool marks were produced with a flat-head screwdriver and a framer's hammer with a check design on the hammer's face. When used to obtain impressions from the barrel of a Smith & Wesson 9mm handgun, the procedure was easy to perform and produced clearly visible impressions of the chamber and lands and grooves. In addition to describing the testing procedures, this article describes the features and application of AccuTrans. 1 table