A 21-year-old man described as "vulnerable and gullible" was beaten to death by a gang who considered him a paedophile, a court has heard.
Shaun Rossington, of Lincoln, was lured to Searby Road in the city by a 13-year-old girl on the promise of a sex act, Nottingham Crown Court heard.
His body was found face down on grassland on 3 June. He died from lack of oxygen, the court heard.
Two men, two girls and three boys deny murder.
The jury was told the seven defendants lured Mr Rossington, beat him and then hatched a plan to cover up their involvement.
The seven include Nicholas Shelbourne, 27, of Edinburgh House, Laughton Way, Lincoln; Mark Jackson, 20, of Yarborough Road, Lincoln, two girls aged 17 and 14 and three boys - two aged 17 and another aged 16.
Prosecutor Richard Latham told the jury one of the 17-year-old boys had pleaded guilty to manslaughter and perverting the course of the justice, while the other 17-year-old boy admitted perverting the course of justice.
Nottingham Crown Court heard the gang originally told police they had stumbled across Mr Rossington's body, claiming he was a stranger.
Mr Latham said when police investigated they found Facebook conversations between the 13-year-old girl and Mr Rossington less than two hours before it is believed he was killed.
The court heard the 13-year-old girl told police the other girl in the group texted Mr Rossington pretending to be her and offering to perform a sex act on him for £100.
The girl told police she had no intention of performing the sex act, but planned to "get the £100 and run".
Mr Latham said at the end of the attack, all seven defendants must have known the 21-year-old was seriously hurt, but did not call for help.
The court heard the group all gave slightly different accounts of events that night, claiming they only left the flat to order a pizza, which prosecutors said was a lie.
The trial continues.