NCJ Number
185001
Journal
Journal of Forensic Identification Volume: 50 Issue: 5 Dated: September/October 2000 Pages: 470-480
Date Published
2000
Length
11 pages
Annotation
The British Police Scientific Development Branch (PSDB) has undertaken a comprehensive review of all the most commonly used techniques for the enhancement of blood-contaminated fingerprints; this article describes the results of the experiments to date.
Abstract
The broad scope of the project required that the work be divided into three sections: optimization of amido black, other protein stains, and reactive techniques. PSDB currently recommends amido black for the enhancement of fingerprints in blood in one of two formulations based on methanol or water. The water-based formula is recommended for general use at crime scenes and on all surfaces likely to be damaged by methanol treatment. The methanol formula is recommended for use when treating suitable articles in the laboratory, i.e., surfaces that are not affected by methanol. Amido black, which is also known as acid black 1, is a diazo dye that stains protein blue-black. It does not react with the normal constituents of sweat in uncontaminated latent fingerprints, so it should be used in sequence with other techniques when blood-contaminated surfaces are examined. This article describes initial experimental work on nine surfaces typically found at crime scenes; these nine surfaces are in the categories of porous surfaces, semi-porous surfaces, and nonporous surfaces. After describing the experimental protocol, this article explains the preparation of experimental samples, the advantages and disadvantages of current recommended formulations for amido black, and the experimental findings thus far. 1 figure, 1 table, and 10 references