With a new technique, a fingerprint can now reveal much more than the identity of a person. It can now also identify what the person has been touching: drugs, explosives or poisons, for example, reports the New York Times. Writing in today’s issue of the journal Science, R. Graham Cooks, a professor of chemistry at Purdue University, and colleagues describe how a laboratory technique, mass spectrometry, could find a wider application in crime investigations.
The equipment to perform such tests is already commercially available, although too expensive for all but the largest crime laboratories. Smaller, cheaper, portable versions of such analyzers may be only a few years away. Researchers call the technique desorption electrospray ionization, or Desi, for short. The chemical signature could help crime investigators tease out one fingerprint out of the smudges of many overlapping prints if the person had been exposed to a specific chemical, said Demian R. Ifa, lead author of the Science paper.