Add another high-tech gadget to the arsenal of forensic science tools that people love to watch being used on television––the portable latent fingerprint mass spectrometer. A new technology will allow investigators to determine, just by a person's fingerprint, whether they've been handling drugs, explosives, or other substances. The technology is based on mass spectrometry, which has been around for years but currently requires large machines that are prohibitively expensive to all but the largest crime labs and researcher centers. It utilizes a method called desorption electrospray ionization, or Desi, to scale down the size of the mass spectrometer. The journal Science published a report today [subscription required] by R. Graham Cooks, a chemistry professor at Purdue University, describing a new technology he and other researchers have developed to analyze latent fingerprints, or the prints that are lifted off of surfaces someone has touched. The Desi technology that Cooks and his colleagues developed uses a tiny jet of electrically charged liquid that dissolves a small section of the fingerprint and sprays it onto the spectrometer that then analyzes and identifies the residue. The New York Times does raise the possibility that with the proliferation of the technology, there are potential ethical pitfalls. An example would be the use of Desi by employers to scan the fingerprints off employees keyboards to see if they've been handling illicit substances. That could be considered an invasion of privacy.