NCJ Number
114846
Journal
Journal of Forensic Identification Volume: 39 Issue: 1 Dated: (January/February 1989) Pages: 11-22
Date Published
1989
Length
12 pages
Annotation
To better understand why latent fingerprints tend to develop as tonal reversals (developing agent adheres to the background while the area depicting the friction ridge patterns remains free of the developing agent) on plastics, a series of studies were conducted.
Abstract
Initially, these studies used fingerprint powders as the sole visualization agent. Subsequent studies incorporated vapor phase cyanoacrylate 'fuming' in addition to powder processing. Plastic bags and sheet materials were the primary targets of the research. Generally, the DeVilbiss powder blower was least destructive to latent prints on plastics, followed by the magna wand and the traditional brush techniques. Of the magnetic powders, Magna Jet Black consistently gave the best results. Maximum contrast was achieved by processing items with magnetic powders after cyanoacrylate fuming. The likelihood of fingerprint development on plastics was not necessarily diminished by aging; however, the chance of developing a tonally reversed print increased by using abrasive brushing methods. Continued comparative studies of the efficacy of various methods of print development, including the metal deposition technique, should be undertaken. 6 figures, 3 tables, 3 references.