Forensic scientists at Leicester University‘s Forensic Research Centre have been working with Northamptonshire Police to develop a new method that enables scientists to ‘visualise fingerprints’ even after the print itself has been removed.
‘For the first time we can get prints from people who handled a cartridge before it was fired,’ said Dr John Bond, Honorary Fellow at Leicester University and scientific support manager at Northamptonshire Police.
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.
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, showing up a residual fingerprint.
‘The technique works on everything from bullet casings to machine guns. Even if heat vapourises normal clues, police will be able to prove who handled a particular gun,’ said Bond.
As a result of the research, cases dating back decades could be reopened because the underlying 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,’ added Bond.
Dr Bond and Prof Rob Hillman of the Chemistry Department at the university now intend to take the research forward via a three-year PhD studentship which will commence next year. The new project will explore further the corrosion of metal by fingerprint residue.