NCJ Number
196831
Journal
Journal of Forensic Identification Volume: 52 Issue: 5 Dated: September/October 2002 Pages: 551-559
Date Published
September 2002
Length
9 pages
Annotation
This experiment found that the rutile forms of titanium dioxide (TiO2) worked well for developing latent prints on dark surfaces.
Abstract
The development of latent prints on some dark surfaces has often posed a problem, because most processes produce dark colored prints, rendering them difficult to see. A previous effort to visualize prints on dark tape required the use of a fluorescent reagent. TiO2 is a chemical that, for the most part, has been overlooked for its value in developing latent prints. It is a fine, nontoxic, nonflammable, white powder with particles much smaller than a micron in diameter. When used to develop fingerprints, it contrasts well with dark surfaces. When used as a substitute for sticky-side powder, the rutile forms of TiO2 (Kerr-McGee CR-837, CR-880, and Kemira 820) produce excellent results on black electrical tape, with the added advantage of developing prints on both sides of the tape. They were also found to work well on plastic bags and cellophane. TiO2 powder can be used as a white fingerprint powder or may be mixed with water and Kodak Photo-Flo to make a white small particle reagent. The different rutile forms can produce slightly different results. If only one brand of TiO2 is to be used, the Kemira 820 is probably the best choice, since it does a significantly better job in developing prints on the nonadhesive side of the tape, as well as producing excellent results on the adhesive side. Additional testing of the various grades of TiO2 may further improve performance. 5 figures and 3 references