Scientists force confessions from mucky fingerprints

Wannabe criminals would do well to listen to their dear old ma's and wash their hands regularly, or PC Plod will be knocking on the door in double quick time*.

According to boffins at London's Imperial College, minute traces of chemicals are left behind in our fingerprints that could be very useful to police trying to track down a suspect.

The technique could help investigators find out about the crims' diet and race, the scientists claim, as well as identifying traces of dodgy items like explosives, narcotics, and so on.

In addition, the researchers say relatively large quantities of urea in the residue indicate that the fingerprints are from a man. Smaller traces indicate a woman. [Or someone who shakes hands with lots of men perhaps. Like the Queen? Ed]

Conventional fingerprint collection tends to destroy the tiny traces of chemicals we leave behind every time we touch something. But the researchers at Imperial found that using an ordinary gelatine based tape allowed them to lift and preserve this chemical fingerprint.

The prints are then analysed in a spectroscopic microscope to reveal the particular chemical profile associated with the print.

Research leader Professor Sergei Kazarian says the work could help investigators working on difficult cases like arson, where fingerprints are particularly hard to lift.