A Victorian man who killed an intellectually disabled person with a kitchen knife after the other man attacked him with a chisel has been described in court as a "lost soul".
Ismail Yassin, 25, on Tuesday faced the Victorian Supreme Court after earlier admitting the manslaughter of Mohammed Osman on Dorcas Street at South Melbourne in June 2020.
Yassin's barrister Phillip Dunn said his client had pleaded guilty to an "unplanned, spontaneous and unfortunate event".
The two men, Mr Dunn said, became entangled in a brawl after Mr Osman repeatedly asked Yassin if he had any drugs or money and "would not leave him alone".
Mr Osman punched the accused man in the head and attacked him with a chisel. Yassin then produced a kitchen knife and stabbed the victim, leaving an eight-centimetre deep wound, as they fell to the ground.
Mr Dunn said Yassin had been a drug-addicted, nomadic couch-surfer when he killed Mr Osman, an intellectually disabled man who also faced drug problems and had not been seen by his family for about four months.
The barrister described both men as "forgotten people".
"There's something empty and sad about these two men," Mr Dunn told the court.
"These were homeless, disorganised and lost souls."
Mr Dunn also said his client's killing of Mr Osman was a sliding doors moment that eventuated through a chance combination of circumstances.
"I'm not sure the production of a knife is something that happens by chance," Justice Richard Niall responded.
The accused's sister, Filsan Yassin, said her brother was distraught about what he had done and committed to turning his life around.
"I don't think it will ever leave him - he thinks about it every day," Ms Yassin said.
"He knows what drugs can do to somebody. He wants to prevent it in the future and help our community.
"We come from a large family and we're all here to support him."
Mr Osman's sister Katye Omar said the death of her older brother had left a "permanent crack" in their family.
"Watching my mother deteriorate before my eyes has been unimaginably painful," Ms Omar said in a statement.
"Mohammed made troubling decisions at times but he had a heart of gold. We will grieve his absence for as long as live.
"He was one of a kind."
Yassin will be sentenced at a later date.
