Interviewee: Alec Jeffreys. Results of the first murder case using DNA fingerprinting.

What David Baker then did to lead an investigation, an incredibly brave act, without any consultation with me. I mean I first heard about it just listening on the radio. They're going to DNA sample on a voluntary basis the entire local community, of men aged, I think it was between 17 and 34, which was the most likely age bracket for this attacker. So the idea was to try and flush out the true assailant, so what he'd actually launched was the world's first DNA-based manhunt. And it very nearly failed. It wasn't just DNA they were using. It was two stage, first of all get the blood sample, blood group typing, 'cause they had a blood group type on the semen, which would get rid of 90 percent of the people. And then the remaining 10 percent would have been DNA fingerprinted to see if it matched the semen from the victims. And so they actually went through this and the trail ran cold. They couldn't find anybody that matched. And it was just purely by chance some time later that a woman overheard a conversation in a pub, where a man was saying he had been asked to stand in as a proxy for this other man and provide a phony blood sample. And she worried about this and went to the police, told them, and that eventually led to the arrest of the true assailant, one Colin Pitchfork, who got a life sentence for each of the murders. And he, without, without the DNA he, whether he would have been caught, heaven alone knows, and he would have killed again. So here was DNA actually saving lives, saving future victims, it's pretty awesome stuff.

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