NCJ Number
225597
Journal
Journal of Forensic Sciences Volume: 53 Issue: 6 Dated: November 2008 Pages: 1344-1352
Date Published
November 2008
Length
9 pages
Annotation
This study observed the degree of corrosion caused by fingerprint residue on each of 10 different metal elements and 10 metal alloys.
Abstract
The study found that elements alloyed with at least approximately 40 percent copper produced the highest degree of alloy corrosion by fingerprint residue, and these alloys produced an image of the fingerprints that included third-level fingerprint detail, such as pores and their relative location. This property was found to be most acute on 9 Karat gold alloy, and a comparison with both conventional inked and digital (Livescan) fingerprints showed that fingerprints deposited on gold alloy were least susceptible to the obliteration of third-level detail. The corrosion of noble metals, such as silver and gold, is further evidence in support of the authors’ previous studies, which found that metal corrosion was enhanced by the presence of aggressive ions (such as choloride) in eccrine sweat from fingers. This study also documented variation in both the amount and composition of eccrine sweat secreted by different donors. This should be studied further, because the concentration of aggressive ions in eccrine sweat appears to be crucial for the success of fingerprint enhancement techniques that require corrosion of the metal surface on which the fingerprints have been deposited. Examples of the 10 metal elements and 10 alloys were obtained in sheet form from a variety of sources within the United Kingdom. A table lists each metal and alloy, along with its composition and supplier. Details are provided on the methods used. 11 figures, 3 tables, and 24 references