NCJ Number
136824
Journal
Journal of Forensic Identification Volume: 42 Issue: 3 Dated: (May/June 1992) Pages: 213-218
Date Published
1992
Length
6 pages
Annotation
This article critiques a case report on the determination of the evaporation rate of latent impressions on the exterior surfaces of aluminum beverage cans so as to determine the age of the prints.
Abstract
The experiment attempted to consider the effects of time and environment on the latent prints by attempting to duplicate those factors; however, the variables in the composition of the latent print residue were only partially recognized, and they were addressed in a limited manner. The researcher proceeded in the experiment with the premise that the latent print residue was either natural perspiration or contaminants from the fried chicken recently handled by the subject. The experiment failed to recognize other possible latent print constituent variation. There are differences in skin secretions at various points on the body, and a person's metabolism as well as emotional and physical condition also affect the quantity of exude. The experiment did not involve sophisticated laboratory procedure. It failed to include the determination of composition, viscosity, and quantity of the latent print residue. Without this knowledge, the evaporative rate could not be established. If all the variables could be determined, scientific protocol requires three additions to the format of any experiment this significant: the use of a blind or even double blind testing to ensure objectivity, a sufficient sampling to establish the repeatability and consistency of the results, and adequate photographic documentation to ensure that any other examiner could reach similar conclusions when reviewing all the material. 12 references