High Resolution Imaging of Latent Fingerprints by Localized Corrosion on Brass Surfaces

• NCJ Number: 229682
• Journal: Journal of Forensic Sciences Volume: 55 Issue: 1 Dated: January 2010 Pages: 58-65
• Author(s): Alex J. Goddard, M.Chem; A. Robert Hillman, D.Phil; John W. Bond, D.Phil
• Date Published: January 2010
• Length: 8 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

This article discusses high resolution imaging of latent fingerprints using the Atomic Force Microscope.

Abstract

The Atomic Force Microscope (AFM) is capable of imaging fingerprint ridges on polished brass substrates at an unprecedented level of detail. While exposure to elevated humidity at ambient or slightly raised temperatures does not change the image appreciably, subsequent brief heating in a flame results in complete loss of the sweat deposit and the appearance of pits and trenches. Localized elemental analysis (using EDAX, coupled with SEM imaging) shows the presence of the constituents of salt in the initial deposits. Together with water and atmospheric oxygen - and with thermal enhancement - these are capable of driving a surface corrosion process. This process is sufficiently localized that it has the potential to generate a durable negative topographical image of the fingerprint. AFM examination of surface regions between ridges revealed small deposits (probably microscopic "patter" of sweat component or transferred particulates) that may ultimately limit the level of ridge detail analysis. 1 table, 11 figures, and 25 references (Published abstract)