Fatal stabbings may be 'trauma response'

A man who stabbed another man in the heart after being attacked with an axe may have suffered a trauma response when he acted in self-defence, a Sydney court has been told.

Eric George Russell faced a sentence hearing on Thursday following a jury decision over the stabbing deaths of Damien Roach, 40, and Leah Mumbulla, 34, in the western Sydney suburb of Cartwright in December 2019.

He was acquitted of murdering Ms Mumbulla and found guilty of Mr Roach's manslaughter.

Russell's lawyer told the NSW Supreme Court on Thursday the 37-year-old had previously faced hardship in the form of racism and mental health issues.

"He had a history of adversity predisposed to a lack of self-control and emotional regulation," the defence said.

The court was told Russell had been diagnosed with post traumatic stress disorder and displayed complex trauma symptoms following the incident, as Justice Richard Cavanagh considered his sentence.

"When someone is placed in imminent fear of death, then that trauma symptomatology has a part to play in the objective seriousness," Russell's barrister said.

The defence conceded he had not been formally diagnosed with PTSD at the time of the offence and the Crown said there was no evidence to link the mental impairment to his actions.

"He had a history of trauma, but that doesn't rise to a diagnosis," the prosecutor said.

Russell's reaction after learning of the deaths of Mr Roach and Ms Mumbulla - a dramatic and visceral response - signalled that he accepted his actions were some form of excessive self-defence, the defence submitted.

The Crown accepted Russell had shown some remorse but noted his failure to fully accept the jury's verdict.

Justice Cavanagh also noted the contradiction between Russell's not guilty plea and his remorse.

"It is difficult to be remorseful if you feel you had to do it," the justice said.

During the trial, Russell's lawyer said his client's intention had been to cause grievous bodily harm to Mr Roach rather than to kill him.

The 37-year-old was at home alone when he was confronted by Mr Roach over a debt after he had been released from jail, the barrister said.

Russell had told the court how Mr Roach brandished an axe and struck him in the mouth causing a blood wound. He said he went to the bathroom and armed himself with a knife, came out and used it.

But the prosecutor invited the judge to find that Russell had gone downstairs with the knife after hearing a male and female arguing outside, telling them he was sick of them being around.

Russell will be sentenced on February 15.