Watch Real Crime online: Episode 4 Cracking The Serial Killers Code

The story of how double-murderer Colin Pitchfork became the first criminal to be snared by DNA fingerprinting. In the mid-1980s, Pitchfork raped and killed two Leicestershire schoolgirls, but despite exhaustive investigations evaded capture, largely due to a false confession and a bogus blood test which threw police off his scent until a chance remark in a pub redirected them to the true perpetrator of the crimes

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