This work investigated the ambient aging of triacylglycerols (TGs) and other lipids in latent fingerprint residue, utilizing matrix-assisted laser desorption/ionization mass spectrometry imaging.
Despite the common use of fingerprints as a trusted means of identification, no method currently exists to reliably establish the time since deposition of latent fingerprints. A reproducible method of establishing latent fingerprint age would allow forensic personnel to determine whether a latent fingerprint was relevant to a crime. In the current study, unsaturated TGs were found to undergo ambient ozonolysis, resulting in a decrease over time. At the same time, two series of compounds related to the degradation of unsaturated TGs due to ambient ozonolysis emerged with time and were detectable within a single day of aging. Tracking the degradation of unsaturated TGs over time proved to be relatively reproducible in multiple individuals and is suggested as a means of establishing latent fingerprint age. (publisher abstract modified)