Hands on jail cell bars.
© Reuters
A British forensic specialist has developed a way to identify pedophiles using only images of the perpetrator's hands and the novel new system has already helped put a child sex abuser behind bars.

In 2014, Greater Manchester Police enlisted the help of forensic anthropologist Dame Professor Sue Black in an effort to solve a child rape case. The crime in question involved sick footage found on a computer belonging to Manchester man, Jeremy Oketch.

The video showed a man with his face obscured sexually abusing a two-year-old girl. While police investigators were sure that when they first questioned Oketch in July 2014 he was the perpetrator, officers feared that without an admission of guilt he could walk free.

Black and her forensics team were able to successfully show that custody images of Oketch's hands matched those in the abuse video. The process is chronicled in BBC documentary 'The Hands That Convicted A Paedophile'.

The forensic anthropologist says her system of identifying pedophiles from images where they have attempted to avoid detection centers on analyzing skin pigment, scars, creases and vein patterns on a person's hands.

"If we're able to automate, then we would be able to use these algorithms that we'll develop, to sift through the millions of images that are held on databases by police forces around the world," she said of her attempts to roll out the system globally.

"The chances of you being able to link them before have been close to zero, but now you might be able to get to a point of being able to track where these perpetrators have been going around the world."

In Oketch's case, dark pigment under his ring finger nail as well as an indentation on one of his hands were key to the rapist changing his plea to guilty ahead of trial.

Oketch was sentenced to 15 years in March 2015 for the rape of the child, with the Greater Manchester Police issuing a statement that he "deserves every second he will spend in jail."