ISSN: 0022-1198
CODEN: JFSCA
Page Count: 8

Latent Fingerprint Detection Using a Scanning Kelvin Microprobe
Worsley, DA
University of Wales Swansea, Singleton park,

Williams, G
University of Wales Swansea, Singleton park,

Neil McMurray, H
University of Wales Swansea, Singleton park,

(Received 19 July 2000; accepted 23 October 2000)

Abstract

Electrochemical interactions between latent human fingerprints and metal surfaces in ambient air are investigated using a scanning Kelvin microprobe. Inorganic salts present in sweat deposited at fingerprint ridges locally depassivate the metal surface producing a Volta potential decrease of greater than 200 mV. Volta potential patterns may persist for months and prints may be visualized by potential mapping, even when overcoated with a polymer layer. Because the Volta potential differences are produced by involatile salts they persist when the organic components of the fingerprint residue have been volatilized by heating to 600°C.

Keywords:
forensic science, latent fingerprint, print visualization, metal surface, electrochemical mechanism, scanning Kelvin microprobe

Paper ID: JFS15103J
DOI: 10.1520/JFS15103J
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