A forensic scientist was "reluctant" to look for fibres on clothes seized from two men suspected of murdering Stephen Lawrence, the Old Bailey has heard.
Adrian Wain told the court that because of the two-week gap between the stabbing and raids when the clothes were found, he did not believe any fibres would be left.
He said: "Given that there was this two-week gap between the offence and the seizure of the clothes I was reluctant to do the transfer of fibres from Stephen Lawrence on to the suspects. That and with the fact that I understood the attack was brief and contact was minimal."
Gary Dobson, 36, and David Norris, 35, deny taking part in the gang attack that killed Mr Lawrence in Eltham, south-east London, in 1993.
The prosecution alleges that microscopic fibres, hair and blood found on clothes seized from their houses proves they took part in the murder. Tiny traces were found by a cold case squad that began work in 2007.
Mr Wain told the jury that his "first port of call" in 1993 was to examine the suspects' clothes for blood, and that he restricted his research to fibres on Mr Lawrence's outer layers of clothing.
He said: "First of all my understanding was that the contact was brief and that the only contact between the attackers and Stephen Lawrence was to his outer clothing. So my thinking was that I would restrict that to his outer clothing."
The court has already been told that the cold case team expanded their search to look for fibres from Mr Lawrence's red T-shirt, which he was wearing under multiple layers of clothing. They also examined a jacket belonging to Dobson with a microscope and found a tiny blood stain measuring 0.5mm by 0.25mm.
Mr Wain said that using a microscope to search an exhibit was "very rare" in 1993, and that when DNA testing was introduced the following year, the minimum size of stain that they could have analysed was 3mm square.
The trial continues.