A teenager has told the Perth Children's Court that his cousin tried to "pickpocket" Tauri Litchfield and then punched him to the ground before a group of boys facing trial for murder chased the sailmaker and he fatally fell from a ledge.
Giving evidence this morning, the 17-year-old said his 14-year-old cousin had put his hand near Mr Litchfield's back pocket as they walked down Pinjarra Road.
He said it prompted Mr Litchfield to slap his cousin on the back of his head with an open palm.
He told the court his cousin reacted by punching Mr Litchfield with a closed fist to the jaw, knocking him onto his back into bushes.
He said his cousin and another five teenagers, who have all pleaded not guilty to murdering Mr Litchfield in Mandurah on March 17 last year, then surrounded the 28-year-old and were "shaping up" to him.
He said two of the boys in particular, his cousin and a 16-year-old, were trying to fight Mr Litchfield.
He and two other boys had held back and the six chased Mr Litchfield, who was telling the boys to stop and leave him alone before he ran from the group.
The teenager, who is not named to protect the identity of the accused juveniles, gave evidence from a separate room on a video link.
He said when the boys returned after about three minutes, one told him that the man had fallen over, hit his head and was lying in a car park.
His cousin had urged them to hurry up and leave and the boys had caught a train.
The trial continues.