Tiny blood, hair and fibre samples that prosecutors claim were linked to black teenager Stephen Lawrence were found on the clothes of two men accused of his murder, a court heard today.
Prosecutor Mark Ellison QC outlined to a jury how modern forensic techniques were used to detect the traces more than a decade after the 18-year-old's murder.
Mr Lawrence was stabbed by a gang of white youths at a bus stop in Eltham, south east London in April 1993.
Gary Dobson, 36, and David Norris, 35, both of south London, deny the murder.
A cold case review was started in 2007 during which forensic experts re-examined clothing seized as part of the original police investigation.
Mr Ellison said that new evidence was found that "consists of the finding of textile fibres, blood and hair linked to Stephen Lawrence on clothing seized from the defendants as part of the original investigation in 1993".
The court was told that a tiny bloodstain found on Dobson's grey jacket was a billion-to-one match to Mr Lawrence's DNA.
Mr Ellison said some of the blood on the collar had soaked into the fibres, suggesting it had been wet and had come from the attack.
There were also minute flecks of blood on the jacket itself which had been found by microscopic examination. These did not contain a full DNA profile.
In total there were 16 fibres which could have come from three separate items of clothing worn by Mr Lawrence, found either on the jacket or its bag, the jury heard.
Two hairs were found in an evidence bag used to store Norris's jeans, one of which was 2mm long and was found to match Mr Lawrence's DNA to a certainty of one in 1,000.
A total of seven fibres were also found on Norris's sweatshirt which potentially came from two items of Mr Lawrence's clothes, the jury was told.
Earlier the court heard that the 18-year-old student was attacked after being surrounded by a group of white men as he and his friend, Duwayne Brooks, waited for a bus in Well Hall Road, Eltham, south east London, in April 1993.
Mr Ellison said: "One of the group was heard to say 'What, what nigger?' and at the same time the whole group rushed towards them."
Mr Brooks managed to run off after shouting "Get up and run, Steve."
But, Mr Ellison continued: "Stephen Lawrence did not manage to get away. The group quickly surrounded him.
"One witness described that he was swallowed up by the weight of numbers and forced to the ground."
Medical evidence suggested one of the two stab wounds to his torso was inflicted when he was standing, the other when he was on the ground.
Mr Ellison said the attackers were "a group of like-minded young white men who acted together in the execution of this attack".
"They reacted together as one on seeing two black men. The only discernible reason for the attack was the colour of his skin."
He said the group "shared the same racial animosity or motivation".
Mr Lawrence's parents, Doreen and Neville, sat feet away from the accused as the jury of eight men and four women was sworn in. One of the jurors is black.
As the case was opened, Mr Lawrence left the court but returned later as the scientific evidence was outlined.
Defending Dobson, Timothy Roberts QC, told the jury that the clothing had been contaminated while in police custody and the evidence amounted to only "a teaspoon".
Stephen Batten QC, for Norris, agreed with Mr Roberts' claims about possible contamination and claimed that the jeans and sweatshirt had belonged to Norris' brother.