A "code of silence" stopped a group of boys giving evidence about the alleged stabbing murder of their mate more than 20 years ago, a Melbourne court has been told.
Karl Michael Hague, 44, is on trial in the Supreme Court of Victoria for the May 1995 murder of 16-year-old Ricky Balcombe in Geelong's Market Square.
Prosecutors claim Hague, who admitted beating the boy on another occasion, killed Ricky in retribution for knifing his car.
The possibility the pair was involved in a drug deal gone wrong has also been raised during the trial.
On Tuesday, prosecutor Andrew Tinney SC began his closing address to the jury, urging them to accept evidence from a key witness, Ricky's friend Paul Bellia.
Mr Bellia previously said he saw Hague stab his mate to death.
Mr Tinney also encouraged the jury to understand why witnesses - many of them gang mates with Ricky - didn't come forward earlier.
"You need to consider what the dynamic was like for these young people ... and the kinds of lives that they were living," he said.
He reminded the jury of the pre-recorded testimony of Ricky's friend Christopher Lawson, who has terminal cancer.
Mr Tinney said Mr Lawson described a "code of silence" where "you don't sell out on your mates".
"Still to this day I believe in that code," Mr Tinney quoted Mr Lawson.
He also reminded the jury the boys were "shit scared" of speaking out after what happened to Ricky.
Mr Tinney described the murder as a "vast, vast overreaction" and an act of retribution on Hague's part for past tensions between the pair.
The jury is expected to consider its verdict early next week.