Post by cruororism on Oct 10, 2003 19:56:49 GMT
The use of forensic evidence such as DNA may seem commonplace in modern times, but it wasn't always so.
The first murder conviction that used DNA evidence to prove the guilt of a defendant involved the murder of two teenage schoolgirls.
And the forensic evidence actually proved the innocence of the main suspect.
Two teenage girls were murdered in the small town of Narborough, Leicestershire, in 1983 and 1986. These events sparked a murder hunt that was only to be resolved by a innovative DNA mass intelligence screen, which eventually led to the conviction of a local man, but not before the prime suspect was proved to be innocent.
In 1983, 15-year-old schoolgirl Lynda Mann was found raped and murdered in the Narborough area. Forensic scientists visited the scene, and a semen sample taken from her body was found to belong to a person with type A blood, and an enzyme profile that matched only 10 per cent of the adult male population. Unfortunately, with no other leads or forensic evidence, the murder hunt was eventually wound down.
Three years later, Dawn Ashworth, also 15, was found strangled and sexually assaulted in the same area. Police were convinced that the same assailant had committed both murders, and the FSS recovered semen samples from Dawn's body that revealed her attacker had the same blood type as Lynda's murderer.
Exoneration
The prime suspect was a local boy, Richard Buckland, who after questioning revealed previously unreleased details about Dawn Ashworth's body. Further questioning led to his confession, but he denied any involvement in the first murder of Lynda Mann.
Convinced that he had committed both crimes, Leicestershire police contacted Dr Alec Jeffreys at Leicester University, who had developed a technique for creating DNA profiles.
Using this technique, Dr Jeffreys compared semen samples from both murders, against a blood sample from Richard Buckland, which conclusively proved that both girls were killed by the same man, but not by him. Surprised and disappointed, the police contacted the FSS to verify Dr Jeffrey's results and decide which direction to take the investigation.
Richard Buckland became the first person in the world to be exonerated of murder through the use of DNA profiling. Dr Jeffreys said: "I have no doubt whatsoever that he would have been found guilty had it not been for DNA evidence. That was a remarkable occurrence."
Leicestershire police then decided to undertake the world's first DNA mass intelligence screen. All adult males in three villages - a total of 5,000 men - were asked to volunteer and provide blood or saliva samples. Blood grouping was performed and DNA profiling carried out on the 10 per cent of men who had the same blood type as the killer.
All of the mass screening work was carried out by the FSS, a painstaking task that took six months to complete, and when they discovered that no profiles matched the profile of the killer, it seemed that all possibilities had been exhausted.
A twist in the story
However, the investigation took a strange twist when a year later a woman overheard her colleague, Ian Kelly, bragging that he had given his sample whilst masquerading as his friend, Colin Pitchfork. Pitchfork, a local baker, had apparently persuaded Kelly to take the test for him. Pitchfork was subsequently arrested and his DNA profile was found to match with the semen from both murders. He was eventually sentenced to life imprisonment for the two murders in 1988.