NCJ Number
199512
Journal
Journal of Forensic Identification Volume: 53 Issue: 2 Dated: March/April 2003 Pages: 149-159
Date Published
March 2003
Length
11 pages
Annotation
This article describes an experiment which shows that a combination of titanium dioxide and methanol provides a simple, safe, and effective chemical solution for treating patent blood fingerprints on dark nonporous surfaces.
Abstract
Current methods used to develop and enhance patent blood prints on dark surfaces lack the reliability and ease of use desired by latent print examiners and crime scene analysts. The method described in this article does not require an alternate light source, and it is easy to use. By applying titanium dioxide suspended in methanol using a simple two-step, spray-and-rinse method, an examiner can enhance patent blood prints and develop bloody ridge detail that had been undetected during the original visual exam. Because the titanium dioxide is in a methanol carrier, fixing the blood print before treatment is not necessary. The end result is white ridges that can be seen under normal light conditions, showing first, second, and third-level detail. The optimal concentration of the chemical mixture was found to be 1.0 g of titanium dioxide to 10 ml of methanol. The mixture was obtained by combining the components directly in the spray bottle used in the application. For semiporous surfaces the results of this method were much more varied, and the results with porous surfaces were poor. 3 tables, 7 figures, and 4 references