Ice-fuelled rage linked to Vic death

A father of two who went to the aid of a pregnant woman was stabbed to death by her boyfriend in an ice-fuelled rage.

Roger Bertocci was stabbed many times when he tried to intervene in a fight between Jonathon Sporton and his pregnant girlfriend in Altona North in December 2014, a Melbourne court has been told.

Sporton, 22, pleaded guilty to murdering Mr Bertocci when he faced the Victorian Supreme Court on March 8 for what was to be the beginning of his trial.

In court on Friday Sporton's lawyer Richard Edney said he had a lengthy history of psychiatric issues and his use of methamphetamine had "escalated" in the weeks before the incident.

The court heard he had been arrested two weeks earlier after becoming paranoid and delusional, which included accusing his girlfriend of sleeping with his best friend.

Sporton showed no emotion as family and friends of Mr Bertocci had their victim impact statements read to the court on Friday.

All of them said their lives had changed for the worse since Mr Bertocci's death and they could never forgive his killer.

The plea hearing continues.