All about the DNA Revolution

On November 23, 1983, a fifteen year-old schoolgirl named Lynda Mann walked along a path known as the Black Pad in the small village of Narborough, England. She was found there the next day, strangled and raped. The only clue was a semen sample that identified the killer's blood as Type A, and the absence of leads left the case unsolved.

Almost three years later, Dawn Ashworth, also 15, was found raped and murdered on another footpath only a mile from where Lynda Mann had met her demise. The semen proved that the blood type was the same, which made it likely that the same man had killed both girls.

Then Richard Buckland was arrested and he confessed to the second murder, but denied any involvement in the first. Investigators felt sure they could nail him for both, and since the family sought justice, they decided to try a new and untested technique: "genetic fingerprinting" through DNA analysis.

Dr. Alec Jeffreys, a geneticist, had discovered this technique and had successfully used it in a paternity suit. He had never before been approached to try genetic fingerprinting in a criminal case, but everyone felt certain that Buckland's semen would prove their case, as well as affirm the technique's viability, so they went ahead and tested a sample of his blood.

To everyone's surprise, there was no match between him and either of the samples taken from the two murders. The test was done again, and once again proved negative. Buckland was exonerated—the first person in criminal history to be freed based on a DNA test. When asked why he had confessed, he said that he'd felt pressured. Investigators believed that he had probably come upon the body, which explained how he knew unpublished details about the crime scene, and they had simply worked him into a confession based on that.

Then the search was on to find the right man, so all the men of Narborough and villages nearby who had type A blood were asked to voluntarily submit to a DNA analysis. Over 5,000 men agreed to do it, but the object was to find any man who would not willingly submit, because it could be that he had something to hide.

Colin Pitchfork, who had once been arrested for indecent exposure, persuaded a friend to go to the test site in his place. Pitchfork provided his friend with a false passport, but the friend had a big mouth. When he bragged about what he did, a woman who overheard him turned him in to the police. That placed the spotlight dead on Pitchfork. He confessed, his genetic profile proved to be indistinguishable from that of the semen samples, and in 1987 he became the first person to be convicted for murder based on genetic fingerprinting.

As evident from the Simpson case, however, DNA was not to have an easy acceptance in court. Let's see how the testing procedures work.