NCJ Number
238791
Journal
Canadian Society of Forensic Science Journal Volume: 45 Issue: 1 Dated: March 2012 Pages: 22-35
Date Published
March 2012
Length
14 pages
Annotation
This study investigated the possibility of validating a proposed Acid Yellow 7 chemical enhancement technique.
Abstract
Impact patterns that are generated on dark surfaces can become camouflaged creating difficulties with conventional photographic methods that are used when estimating the area of origin. Chemical enhancement is an alternative technique that can be used to visualize these latent bloodstains. The application of Acid Yellow 7 to already fixed bloodstains provides a robust enhancement protocol which yields minimal stain distortion. Image J software was utilized to count stains, resulting in an approximate 5 percent increase in small stain detection post-enhancement. Area analyses also performed with Image J demonstrates that the average area of a single stain increases by a factor of approximately 1.24 post-enhancement. When using the BackTrack suite of programs this enlargement does not significantly affect the calculated impact angle of an enhanced bloodstain when compared to that of its original deposition (P=0.585). As a result, the area of origin can be estimated within the accepted error of plus or minus 7 cm from the known blood source. (Published Abstract)