IT is commonly said that if you understand something, you know it like the back of your hand. But few know that part of a person’s anatomy quite like Dr Helen Meadows, a forensic anthropologist at Dundee University.

Her work studying veins, lines and freckles that abound on the backs of hands helped prove each one is a unique biological signature that could help identify people who want to keep their identity secret.

And it has led to the successful imprisonment of paedophiles across the world, opening up a new front in the war against child abuse.

The 35-year-old scientist has been sharing her knowledge in a new 10-part TV series looking at the role of the police and other experts in some of the most challenging murder cases in the UK and America. But it is her work behind the scenes in recent high-profile paedophile cases that has had the greatest impact.

She said: “It’s been known for a long time the patterns on the back of your hand are unique. Your right hand will be different to your left, and even those of identical twins will not match up under examination. Everybody’s hands are different. But we were the first group to take that and use it and prove it could be used for identification in court cases.”

It is an ugly truth that many paedophiles feature in the pictures of their abuse, but take pains to keep their face out of the picture or digitally scramble it to make it unrecognisable. But often they will leave their hands visible, giving Ms Meadows and her team a window with which to work.

Working with carefully sanitised images, their work has been instrumental in sending child abusers behind bars, all because they could identify them simply by looking at their hands.

Ms Meadows added: “It is typically men in these pictures. They will make sure you can’t see their faces, but they seem to like to have their hands in the photograph. We do not know why, but it’s very common.”

Among those snared through this technique was paedophile David Morrison, from Grangemouth, who was jailed after he raped a 14-month-old girl and posted the images on the internet. Another put behind bars was Dean Lewis Hardy, who took indecent photos of four girls aged between eight to 10, including images of his hand touching them, during a holiday in Thailand.

Ms Meadows, a former post-doctoral researcher at the university’s Centre For Anatomy And Human Identification, led its highly successful massive open online course Identifying The Dead and is developing new online courses.

The television series How I Caught The Killer is running on Sky Witness and lasts for 10 weeks. Produced by Woodcut Media, the series, which is narrated by former police officer and Crimewatch presenter Rav Wilding, takes an in-depth look at what it is like to be a police officer working on murder cases. Ms Meadows is on screen talking about the forensic investigation involved in the cases.

“What appealed to me about this series is the holistic approach the production team wanted to take , looking at all individuals and teams involved in solving a crime and the fact that I was able to carry out my own research,” she explains.

“I was given eight cases to work on and I had access to some of the case notes from the original investigation teams. My task was to clarify certain points in the case and answer specific questions, ranging from basic queries about sampling to what interested me from a forensic point of view in a case.

“Forensic science isn’t the sole focus of the series. The production team has gone beneath the surface of these investigations and looked at the different people involved in solving them. They talk to family liaison officers, the original investigation teams and the families.”

She added that the series includes landmark cases, including Colin Pitchfork, who was given life imprisonment for the rape and murder of two teenage girls in the 1980s and was the first person convicted of murder based on DNA fingerprinting evidence, and Daniel Rosenthal, who was convicted of murdering his mother despite the body never being found.

“The cases are all unusual in some way and very interesting,” she says.