Vic killer to be assessed before sentence

The older brother of a recently convicted Melbourne killer says he had "never, ever" been violent, despite grappling with drug use.

Lawrence Duca was found guilty last week of murdering dressmaker The Phuong Vuong during the furtherance of a violent crime - shooting his victim in the chest twice at his home before robbing him in June 2017.

Mr Vuong had resisted when Duca and another man turned up with a 12-gauge shotgun, but was shot during the struggle.

The robbers made off with $27,000 in cash, a Louis Vuitton bag and a wallet.

Mr Vuong's body was found in his kitchen 10 days later by a friend.

Last week, a Supreme Court jury found Duca guilty of statutory murder - a charge that involves an unintentional killing, but is still deemed murder because of the circumstances.

On Tuesday, Duca's older brother Victor told the court his sibling had struggled with cannabis and ice use since the break-up of his marriage.

"(But) it's never, ever made him violent," he said.

But the court also heard Duca kept a collection of weapons inside his car before the murder.

Duca's pre-sentence hearing was adjourned until May 6, so he can undergo neuropsychologist.