In an earlier post I talked about “Touch DNA,” where DNA can be extracted from some fingerprints. The typical fingerprint is made up of oils, dirt, skin cells, and other debris that are deposited whenever someone touches a surface. The cells left behind are the source of the DNA. But fingerprints reveal much more.
A new technique developed by R. Graham Cooks of Purdue University allows for chemical analysis of fingerprints. This technique is called Desorption Electrospray Ionization or DESI, for short. DESI can reveal drugs, explosives, and other materials the person might have handled. It can even be used when fingerprints are laid down one on top of another by several different people. Each person’s print has a unique chemical make up and it is this difference that allows examiners to separate these piled up prints from one another. The usefulness of this technique in analyzing crime scene prints should be obvious.
Read more about this fascinating new tool: