NCJ Number
233769
Journal
Identification Canada Volume: 29 Issue: 1 Dated: March 2006 Pages: 1-36
Date Published
March 2006
Length
36 pages
Annotation
The two feature articles describe the evaluation of 5-methylthioninhydrin for the detection of fingermarks on porous surfaces, as well as the use of Photoshop CS to produce blended photographic images for rescuing photographs created under poor conditions.
Abstract
The chemical 5-methylthioninhydrin was developed in the early 1990s for treating fingermarks on porous surfaces. Although many researchers showed the promise of this chemical during the years between 1990 and 1997, current research indicates that this reagent is sill not commonly used in casework. The current study assessed the commercially produced 5-methylthioninhydrin and compared it to the more commonly used reagents for detecting fingermarks on porous surfaces. The study found that 5-methylthioninhydrin is superior to ninhydrin; however, 1,2-indanedione produced a much stronger luminescence when used to treat latent fingermarks. Comparable fluorescence was produced with 5-methlthioninhydrin after metal salt treatment to DFO; the high background detracts from the ridge detail, however. The study concludes that although the cost of 5-methylthioninhydrin is higher than for conventional reagents, its use may be justified in some circumstances. The second article begins with an illustrated step-by-step demonstration of the technique for blending two exposures of the same scene. It involves the use of layers within Adobe Photoshop CS and then placing one exposure overtop of another exposure. The best qualities of each exposure are then used in the final print. The article then examines a few applied forensic applications of the blending of two exposures, including a technique for rescuing underexposed images. This issue's section on "Society Business" (Canadian Identification Society) addresses Society awards, the "President's message," the 29th CIS Educational Conference, guidelines for authors, a listing of award winners and past presidents, and a listing of staff members.