Manchester Evening News
A small piece of sticky tape proved to be the silent clue which waited for science to catch up and allow it to speak. The tape, tucked inside half a brown envelope, contained samples taken from Lesley's clothing.
In 1975 forensic scientist Peter Guise had wrapped it around a wallpaper seam roller and rolled it over the inside and outside of Lesley's underwear. At the time he was looking for fibres and blood, unaware that years in the future scientists would be able to create a DNA profile from this or any of the other human cells picked up by the tape.
The tape was one of two pieces which lay in storage before being found at the Forensic Science Service lab in Wetherby in 1999. The were the only things left from the crime scene more than 30 years after the event.
Lesley's clothes had been destroyed in the Eighties when police had thought they had got the right man and scientific glass slides containing scrapings from her clothes were mysteriously lost during Stefan Kiszko's trial.
The tape, identified by a tiny handwritten reference number, was the only clue left to help catch the killer.
Dr Gemma Escott was the scientist who was asked to find the best way to try extract a DNA profile. It was the first time anything like this had been done, and as the tape was the only evidence available she could not afford to lose any by making a mistake.
In July 1999 in a series of controlled experiments with other pieces of tape she devised a method designed to make the most of the evidence and ensure nothing was left to chance.
This involved cutting the 3-4 inch long tapes into 20 pieces and dissolving the two sides apart with chemicals before testing for bodily fluids and if she found them, creating the DNA profile from it. Enough material was found on the tape to create a genetic fingerprint which was then tested against all the scientists who would have touched it without gloves in the seventies and the two existing suspects Stefan Kiszko and Raymond Hewlett. They tested negative.
It was an allegation of sexual assault which brought Castree's DNA profile into the system. At the end of 2005 a woman was found distressed at an Oldham hotel. She said she had been sexually assaulted by a man in one of the hotel rooms. That man was Ronald Castree.
He had arranged the liaison with the woman who worked as a prostitute but she had been upset by what he had in mind. When she complained to the police, he was arrested and asked to give a DNA swab as a matter of routine. The case was not pursued but this decision was not taken before the DNA sample was entered into the national database. It was a billion to one match to the DNA profile of the person believed to be Lesley's killer.
Previous Article
Post a Comment