New fingerprint method could unlock cold cases

By Michael Kahn

LONDON (Reuters) - It's a discovery that would make even Sherlock Holmes proud.

Scientists have developed a new crime-fighting technique that allows police to lift fingerprints from bullets even if a criminal has wiped down a shell casing.

Authorities in Britain and the United States used the method to re-open three cold cases, including a U.S. double murder that police are now optimistic of solving, said John Bond, the physicist who developed the technique.

"In one case there was enough evidence that could lead to an identification of an offender," said Bond, a researcher at the University of Leicester and consultant at Northamptonshire Police.

The conventional method of taking fingerprints has been around for more than 100 years and involves creating a chemical reaction with the sweat left behind on an object to produce an image police can use.

But if a criminal wipes away the sweat, there is little left to react with the chemical and regular methods are useless, Bond said in a telephone interview.

The new technique allows police to outwit a criminal and produce a fingerprint even if there is no sweat impression to work with.

The British experts focused on hair-width bits of corrosion that sweat often leaves on certain metals in bullets and bombs.