Stories tagged corrosion

Dec
16
2008

Fingerprint
FingerprintCourtesy leeechy (jkjond)
Criminals need no longer waste time wiping down or washing the cartridge cases of the bullets they intend on using in a crime to get rid of their fingerprints ahead of time, you will still be caught! Researchers at the University of Leicester and the Northamptonshire police have teamed up to develop a technique to see fingerprints even if a metal surface has been wiped down. When people hold metal objects, the natural residues on their hands, like sweat, corrode metal surfaces. Their technique is particularly useful with cartridge casings, because the heat from shooting the weapon helps to imprint the fingerprints on the metal. Basically, you dust the metal of interest with a fine layer of conducting powder, and then apply an electrical charge to it. This causes the conducting powder to be attracted to the areas where the metal is corroded from fingerprints. Would be criminals would need to use abrasive cleaning techniques to remove the layer of corroded metallic surface to destroy their prints. Now don’t you go getting any ideas!