One of six men accused of torturing and stabbing a 16-year-old girl to death has pleaded guilty to kidnapping her and her friend.
Mary-Ann was found dead in Reading's Prospect Park on 7 May
Joshua Morally, 23, of Balham, London, still denies murder, attempted murder, rape and causing GBH with intent.
The body of Mary-Ann Leneghan was found in Reading's Prospect Park in May 2005. Her 18-year-old friend was found alive with a bullet wound in her head.
Reading Crown Court heard they had been tortured and raped by six men.
Mr Morally changed his plea to guilty shortly before the trial began on Tuesday.
Opening the case prosecutor Richard Latham QC said: "Some were more involved than others, they had various parts, different roles, you have only one trigger on a gun, only one person actually holding the murder weapon, the knife.
"But we suggest that they all had a role to play and they were acting in concert, as lawyers sometimes say, as part of a joint enterprise to torture and kill these two young women."
Mr Latham told the jury the likely motive for the girls' ordeal was that Mr Thomas blamed Mary-Ann for a robbery at his flat in April last year.
Mr Latham said that on the night of 18 or 19 April Thomas was attacked, stabbed and robbed of drugs at the flat on Reading's Oxford Road.
Mr Latham said: "It is clear that Thomas believed that Mary-Ann and/or [her friend] had set him up for that robbery."
The five other defendants are: Adrian Thomas, 20, of Battersea, south London; Llewellyn Adams, 24, of Balham, south London; Indrit Krasniqi, 18, of Chiswick, London; Michael Johnson, 19, of Southfields; and Jamaile Morally, 22, of Balham, south London.
All five men each deny the same nine charges, including one charge of murder, one charge of attempted murder, two counts of kidnap, three counts of rape and two counts of causing GBH with intent.
Joshua Morally denies murder, one charge of attempted murder, three counts of rape and two counts of causing GBH with intent.
Jamaile Morally also denies a further charge of raping Mary-Ann.
The trial continues.