Forensic science workers made series of mistakes handling evidence relating to one of original murder suspects

Stephen Lawrence trial: mistakes were made in the handling of crucial evidence. Photograph: PA

A police forensic science worker made a series of mistakes in handling evidence relating to one of two men accused of murdering Stephen Lawrence, the Old Bailey heard on Wednesday .

Yvonne Turner, a forensic science assistant, put the wrong case number on a jacket belonging to Gary Dobson, who was a suspect in the fatal stabbing of Lawrence in April 1993. She went on to wrongly record that no tapings of fibres had been taken from the jacket – a yellow and grey bomber jacket – and a cardigan belonging to Dobson.

Evidence secured from the cardigan and jacket belonging to Dobson as a result of advances in science, and from trousers and a sweatshirt belonging to David Norris, are key to the crown’s case that the two men were in a group of white youths who attacked Lawrence 18 years ago.

The jury at the Old Bailey was told yesterday that exhibits relating to five suspects – including Norris, Dobson, and two other men not on trial, Jamie and Neil Acourt – were all stored together in 1993 in a disused cell at Eltham police station.

Dobson, 36, and David Norris, 35, deny murder. They claim their clothes became contaminated with blood, hair and textile fibres belonging to Lawrence while being stored and handled by the police and forensic scientists.

Working out of a laboratory in Lambeth, south London, Turner had been asked to examine a jacket belonging to Dobson in October 1993. But she wrote a case number relating to a robbery case she was also working on, at the top of the paperwork for the jacket.

“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,” Turner told the jury.

The court heard she also marked “no tapings” for fibres had been taken from Dobson’s jacket, even though they had.

Turner, who had been working in forensic science full-time for seven years by 1993, made the same mistake with Dobson’s cardigan. She then admitted there had subsequently been “difficulty locating the tapings as they had been annotated with the incorrect case number”.

The scientist, who now runs her own company as a trainer and consultant in forensic science, said she was unable to say when the exhibits were taped for fibres. Her mistakes on the case notes were corrected before 1995 when her work was reviewed.

Detective Constable Robert Crane told the jury that the homes of five suspects, including Norris, Dobson, the Acourts and a fifth unnamed man, were searched in simultaneous dawn raids on 7 May 1993, 15 days after Lawrence was killed.

Crane, who had responsibility for all the items of clothing seized and items belonging to Lawrence, said that some items such as the teenager’s rucksack were stored on a bed inside a disused cell at Eltham police station.

The exhibits from the suspects were placed on the floor of the same cell, either in boxes or large rubbish sacks, he said. But he said he did not mix them up.

The case continues.

• The headline on this article was amended on 24 November 2011. The original headline said: Stephen Lawrence evidence was mislabelled by police, trial told. The mislabelling was done by a forensic scientist.

Sandra Laville, crime correspondent
The Guardian, Wednesday 23 November 2011 21.53 GMT

Find this story at 23 November 2011

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