NCJ Number
225770
Journal
Journal of Forensic Identification Volume: 59 Issue: 1 Dated: January/February 2009 Pages: 80-96
Date Published
January 2009
Length
17 pages
Annotation
This article reports on optimization studies conducted for a new fingermark detection technique called single-metal deposition (SMD), which involves a reduced number of steps as well as simpler and less expensive reagents than multi-metal deposition (MMD).
Abstract
The studies show that although SMD still has the same disadvantages of MMD, i.e., a lack of contrast on dark and patterned surfaces and cumbersome application, it provides much easier laboratory constraints and decreased costs. In addition, it produces the same sensitivity as MMD, because it relies on the same principles of gold colloid attachment on fingermark secretions. SMD is effective on a wide variety of surfaces, both porous and nonporous; however, it had some difficulty on surfaces with a basic pH. The optimized parameters for SMD varied little from the original parameters used in the initial development of the technique. This indicates the robustness of the physical developer process in SMD, which persists under varying application conditions. The first part of the application of MMD is unaltered in the SMD process. In the second part of MMD, the optimized formula calls for a physical developer based on a silver acetate-hydroquinone couple, which requires two consecutive immersions. In SMD, however, this couple is replaced by a gold chloride-hydroxylamine couple similar to the silver-based developer, but for which one immersion suffices. Consequently, this new physical developer reduces the number of steps needed to perform the enhancement, the number of reagents, and the cost. Materials and methods are described for the SMD optimization and the SMD comparison with MMD. 1 table, 9 figures, and 6 references