Recover latent fingerprints on nonporous surfaces using a modified vacuum-Cyanoacrylate Ester (CE) technique
William Bryon
Stones Convak LLC, USA
: Forensic Toxicol Pharmacol 2015, 4:4
Abstract
O ur premise is that the temperature of the substrate material during the fuming event, combined with the relative humidity is crucial in obtaining the best possible fingerprint development and that the specific heat capacity and thermal conductivity of the evidence substrate material enhance the polymerization process involved with heat accelerated vacuum cyanoacrylate fuming. On identical materials with deposited latent fingerprints developed with standard cyanoacrylate fuming and heat accelerated vacuum fuming with cold, we have been able to show that there is a substantial increase in polymerization which is easily observed visually and supported by measurable weight increases when the evidence is cooled using specific heat capacity. We have shown that we can increase the polymerization on the fingerprint ridge site by cooling the temperature of the substrate. When extreme cold is exposed to humidity there is a layer of frost that is deposited on the substrate. In a vacuum environment there is a time where the background humidity evaporates and the latent print retains a portion of that humidity. Once the atmosphere is removed a heating element heats the liquid cyanoacrylate ester (CE) fuming the latent. The temperature difference between the cold item and the heated fume results in an increased condensation of the CE fume. In a vacuum environment the fume adheres only to the latent print and not the background. This has the capability of recovering dried sebaceous latent fingerprints.
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