A boy who saw a woman killed in a park has told a court he is "positive" the boy charged over her death is the one he saw attacking her.
Sophie Lancaster was kicked and stamped upon in the fatal attack
Sophie Lancaster, 20, and her boyfriend Robert Maltby, 21, were attacked by a gang in Lancashire because the two were dressed as goths, a jury was told.
A 15-year-old boy is on trial at Preston Crown Court for murder.
A second boy, also aged 15 at the time of the attack, has already confessed to murder.
Both 15-year-olds, along with three other youths, have pleaded guilty to causing grievous bodily harm with intent to Mr Maltby during the incident at Stubbylee Park, Bacup, in the early hours of 11 August last year.
Sophie Lancaster was kicked and stamped upon in the attack and died two weeks later in hospital.
A recording of a 999 call made by the 15-year-old witness was played to the jury as the youngster and two friends tried to get help to the injured couple.
Andrew O'Byrne, defending, suggested to the boy he had "assumed" the accused had attacked the girl because he was with the gang, and it was "pitch black" on the park so he could not have seen properly.
Robert Maltby and his girlfriend were attacked in August 2007
But the witness replied: "I'm positive. I know it was him. I know I'm not wrong, I know I'm right."
A second witness, aged 17, stopped the initial attack on Mr Maltby, the court heard.
He agreed that "almost everyone" on the park had been drinking cans of lager but said that the defendant, who cannot be named for legal reasons, had "started it" by throwing a punch at Mr Maltby.
The court heard a recording of a 999 call made by the first witness following the attack, but after only a couple of minutes of the graphic audio tape, Sophie's mother, Sylvia Lancaster, left the court in tears.
In the recording, the witness was heard to say: "There's two people been battered, there's blood coming out of their heads and they can't breathe properly..."
"There's blood coming out of her ears and now her eyes."
The trial continues.