The man caught with his trousers up

IN THE world of forensic science, trapping criminals by identifying their DNA and their individual genes is old hat. At least it is in Spokane, Washington State, where local law enforcers are tracking down offenders by their individual jeans.

In a case that could see wised-up criminals ditching their denims for something else, the FBI caught a bank robber after identifying his jeans on a security video.

The man was caught on film in April 1996. Like any bank robber worth his salt he was wearing a mask to cover his face, but part of his trousers were showing on the video footage.

When the film was enlarged the bureau's forensic scientist, Richard Vorder Bruegge, noticed worn patches on the jeans.

Police had several suspects for the robbery and on closer inspection it was noticed that one was wearing a pair of jeans with more than 24 features that matched the "bar code" of the jeans on the film.

The pattern on the jeans is caused by slight imperfections that show up as light and dark lines running across the fabric. They are caused by the way the material is forced through the sewing machines by workers sewing the seams. The fabric gets bunched and the raised portion is worn away, creating white bands.

At the trial, the accused's defence team tried to discredit the "jean gene" theory by introducing 34 similar pairs. But the FBI was able distinguish every pair from those of the accused and the man was convicted.