Scientists from the University of Leicester, working with the scientific support unit of the Northamptonshire Police in England, have developed a technique that will enhance fingerprints on metal objects from small shell casings to large machine guns.
Wiping It Down Won't Help"For the first time we can get prints from people who handled a cartridge before it was fired," said Dr. John Bond, the scientific support manager for the Northamptonshire Police. "Wiping it down, washing it in hot soapy water makes no difference - and the heat of the shot helps the process we use."
"The procedure works by applying an electric charge to a metal - say a gun or bullet - which has been coated in a fine conducting powder, similar to that used in photocopiers," Bond said in a news release. "Even if the fingerprint has been washed off, it leaves a slight corrosion on the metal and this attracts the powder when the charge is applied, so showing up a residual fingerprint. The technique works on everything from bullet casings to machine guns. Even if heat vaporizes normal clues, police will be able to prove who handled a particular gun."
Cold Cases Could Be SolvedDr. Bond believes the new technology could be used to reopen cases going back decades, because the underlying corrosion print never disappears.
"It's certainly possible hundreds of cold cases could be reopened because with this method the only way to avoid a fingerprint being detected is through abrasive cleaning as that takes a layer off the metal," Bond said.
Dr. Bond's findings were initially published in the Journal of Forensic Science.