Scientists are appealing to the public to submit photographs of their hands in the hope of developing new tools to track down and convict child abusers.
A team at Lancaster University are aiming to create a database of images which will allow child abusers to be identified by the features on the back of their hand, in the same way fingerprints are used.
In the past, suspects have successfully been identified by the patterns of veins, tendons and freckles on their hands, which have been matched to hands seen in images of abuse.
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The process of identifying suspects by their hands is currently very slow, but forensic anthropologist, Professor Dame Sue Black of Lancaster University, believes computer algorithms could speed things up.
"A lot of the photographs we look at when it involves child abuse, it's the back of the hand we see, not the front of the hand," she told BBC Radio 4's Today programme.
"There are so many anatomical features in there that we've been able to use those to help the police in the past to compare images between suspects and offenders."
'We need to be able to train machines'
She added: "We need to be able to train machines to do the machine learning that extracts the information we see from the photographs and creates an algorithm that will allow us to search databases that the police hold and perhaps be able to link cases that they've not been able to in the past."
Scientists are looking for 5,000 volunteers to send in hand photographs to help train the machines.
"We will strip out all the information that will identify somebody, so we won't be able to link that photograph back to somebody's email or name," Professor Black added.