Lawrence trial forensic expert admits: 'I made crucial mistake'

Evidence from jacket of defendant was wrongly labelled with a code from a different case

One of the first forensic scientists to investigate the murder of black teenager Stephen Lawrence was forced to concede yesterday that she had made a crucial error in labelling evidence.

Yvone Turner, who is now a consultant in forensics and a trainer, admitted that practices in the early Nineties were light years away from the procedures she teaches today. Whereas scientists are now expected to wear face masks, hair nets and disposable coats to avoid contamination, she did not even wear gloves.

Earlier in the day the murder trial at the Old Bailey heard that brothers Neil and Jamie Acourt were originally suspects in the case and evidence from their home was placed in the same disused police cell as the current defendants, Gary Dobson, 36, and David Norris, 35, as well as a fifth person.

Mr Lawrence, 18, was on his way home on 22 April 1993 when he was set upon by a group of racist thugs and stabbed twice. He died in hospital a short while later in what was to become one of the most notorious murders of recent history. Both Mr Dobson and Mr Norris deny murder.

Exhibits officer Detective Constable Robert Crane conceded that evidence from all five people was placed in the same room but said it had been stored in separate evidence bags before being sent to the Metropolitan Police Forensic Science Laboratory where Ms Turner began examining it. Yesterday the scientist admitted she had made a mistake with tapings from Mr Dobson's grey jacket, mislabelling the evidence with a code from a robbery she was also working on.

The jacket is now a central point of the prosecution case after a review of the investigation in 2007 found a blood spot and flecks on it as well as fibres from Mr Lawrence's clothing on tapings and in the original exhibit bag. The defence is arguing that this was the result of cross contamination over the years.

Conceding that on an evidence sheet on 28 October 1993, she had also written "no tapings" for the jacket, she said: "I wasn't concentrating and I wasn't focused at the stage when I wrote the case number in, but I've clearly got to grips with the case as I've written the correct item number."

She had no idea, she said, when the error was corrected and could not recall when the tapings from the jacket were made between October 1993 and August 1995, when they formed part of a review for a private prosecution, or why there was no note of such an examination.

Under cross examination from Timothy Roberts QC, for Mr Dobson, she admitted it was "highly irregular" that a "careful, methodical" scientist would go through all the procedures required and then forget to make a note.

She admitted to Stephen Batten QC, for Mr Norris, that scientists in the early Nineties it would be "common practice" to put bags containing the victim's clothing in a larger sacks with suspects' items, though it was now no longer considered proper procedure.