A jacket belonging to Stephen Lawrence was stored in the same outer bag as clothing seized from one of the men suspected of his murder, a court has heard.
Christopher Bower, a stores worker at a forensics laboratory in Lambeth, south London, told the Old Bailey that it was not standard practice to separate victims' and suspects' exhibits after they had been examined by scientists.
Gary Dobson, 36, and David Norris, 35, deny taking part in the gang attack in which Mr Lawrence was killed in Eltham, south-east London, in 1993.
The prosecution argues that tiny amounts of fibres, blood and hair found on clothes seized from their homes prove they were involved in the murder of the 18-year-old student. But the defence says the samples got on to the clothes through contamination during handling and storage.
Mr Bower told the Old Bailey that, when exhibits in the case were returned to police from the lab in November 1995, a cardigan and jacket seized from Dobson's house were put in the same plastic sack as Mr Lawrence's black Raiders jacket.
However, all the items were sealed individually in paper evidence sacks, he told the court.
During cross-examination, Timothy Roberts QC, for Dobson, asked him: "When you made a choice as to which packages should go into the same overbag together, what criteria informed that choice?
Mr Bower replied: "There was no criteria - random packages from the same case would go into an overbag."
Later, Mr Roberts asked him: "There was no anxiety in your storeroom about these packages being co-mingled together?"
Mr Bower said: "Not at all, no."