| Last updated
For over 20 years Harold Shipman appeared to be respected GP, a pillar of the community, but really, he was a truly evil man who potentially killed hundreds of innocent people.
Now experts believe they have discovered the moment the serial killer, also known as 'Dr Death', gave away his murderous actions.
In a new show, premiering this Friday on Investigation Discovery at 10pm, Faking It: Tears Of A Crime experts have analysed Shipman's psychology, body language and speech from various interviews and say how they think he subconsciously gave it all away in nine seconds.
Shipman was convicted back in 2001 and was later questioned further by police in connection with hundreds of suspicious deaths while he was a working as a doctor in West Yorkshire.
During one interview, a body language analyst named Cliff Lansley said though Shipman tried his best to give nothing away - keeping his back turned towards the officers - he managed to let slip due to his breathing freezing for nine seconds.
The change in the breathing came about when he was shown a picture of Elizabeth Pearce - one of the unfortunate victims of Shipman.
Cliff Lansley said: "He must be experiencing fear. How do we know? Because in fear, like our ancestors if they were threatened by a large animal, they'd freeze."
It's at this point Lansley said Shipman's guilt becomes apparent.
He added: "That freeze response is a psychological-physical reaction. This is subconscious. This is the point he stops breathing, and he knows the picture is there... He doesn't breathe for nine seconds. So, Elizabeth Pearce - that name is a problem for him."
Sir Richard Henriques QC was part of the Prosecution Counsel who help put Shipman behind bars. In the documentary he explains how the true extent of Shipman's crimes are completely unknown and the actual number of his victims could be massively higher than the number he was convicted for.
He said: "The public enquiries reached 420 on the basis of balance of probabilities, but he was given the benefit of the doubt in a number of cases and so yes, it could have been more."
Shipman isn't the only murderer to go under the microscope during the documentary - experts also look into a police interview tape of James Warnock.
Warnock murdered Yiannoulla Yianni back in 1982 and was finally convicted 30 years later. Experts believe they can pinpoint the moment he gave himself away too.
Chosen for YouChosen for You
Most Read StoriesMost Read