NCJ Number
246562
Journal
Journal of Forensic Sciences Volume: 59 Issue: 1 Dated: January 2014 Pages: 211-218
Date Published
January 2014
Length
8 pages
Annotation
The application of vacuum metal deposition before scanning Kelvin probe visualization of fingerprints is investigated.
Abstract
The application of vacuum metal deposition before scanning Kelvin probe visualization of fingerprints is investigated. The potential contrast between fingerprint ridges and furrows is maximized by the use of silver deposition for non-noble metals and gold-zinc deposition for noble metals. The higher susceptibility of eccrine fingerprints to vacuum metal overdeposition is confirmed. Additionally, fingerprints are best developed individually and by building the metal deposition slowly to protect against overdevelopment and variation in the rate of metal condensation. The progress of the metal deposition can be monitored using the scanning Kelvin probe by reference to the change in potential and continuity of the new potential on the surface. The use of acetic acid solution for the recovery of overVMD-developed samples is shown not to be useful. Applying the metal deposition has the additional prospect of increasing surface conductivity and homogeneity and both can aid fingerprint visualization using the scanning Kelvin probe. Abstract published by arrangement with Wiley.