A DJ and a party goer were killed by the same bullet which travelled through the first victim and a wall to claim a second life, the Old Bailey has heard.
Iain Davis allegedly shot Ashley Kenton, 22, to stop him leaving the party in Shore Road, Hackney, east London, on New Year's Eve in 2002.
The bullet hit the DJ in the neck and went through the plasterboard wall and struck Wayne Mowatt, 29, in the head.
Mr Davis, 33, of Brixton, south London, has denied two counts of murder.
The accused, who had gone to the party which was held in a flat, had been seen arguing with Mr Kenton, also known as DJ Creation, before the shooting.
He tried to prevent the DJ from leaving as the party's organisers brought the event to an end, the court heard.
Edward Brown QC, prosecuting, told the retrial hearing: "There can have been no other intention in the mind of the defendant than that Ashley Kenton would die. It was little less than a callous execution.
"What had started as a celebration in that flat, ended in a bloodbath."
The second victim Mr Mowatt, "who was standing probably quite oblivious of the events going on the other side of the wall", died when the same bullet pierced the wall and entered his head.
Mr Brown added: "He was truly in the wrong place at the wrong time."
Mr Davis fled to the US with a fake passport soon after the shooting, where he was arrested in August 2003 for not having a valid visa, the jury heard.
The trial continues.