Shaun Johnson not guilty of stabbing murder of Steven O’Brien at Mayfield

Shaun Johnson has been found not guilty of murder after slashing the throat of Steven O’Brien at a Boxing Day gathering in Newcastle.

A Newcastle man who slashed the throat of a friend at a backyard Boxing Day barbecue has been found not guilty of murder, and will instead be sentenced for manslaughter.

Shaun Garry Johnson, 38, was acquitted after a week-long judge-alone trial in the NSW Supreme Court.

He previously pleaded guilty to the lesser charge of manslaughter, claiming excessive self defence.

Steven O’Brien died from a knife wound to the neck on December 26, 2019. Picture: Facebook.

Throughout the trial the Crown claimed Johnson stabbed Steven O’Brien, 50, in the neck in an unprovoked attack, after accusing the victim of sleeping with his partner.

But the defence argued Johnson was defending himself against an assault by a third man, Billy Gee, and that Mr O’Brien had likely come between the pair.

“The target, in our submission, was probably Mr Gee and not Mr O’Brien at all,” defence barrister Chris Watson said in closing arguments.

“There was a significant threat put upon the accused … particularly by Mr Gee.”

Police at the scene in Mayfield.

The court heard Johnson, Mr O’Brien and Mr Gee were drinking at Mr O’Brien’s Mayfield home for several hours on December 26, 2019, before the attack occurred.

“There was no evidence of anything that occurred up to that time that could have caused the accused to do what he did,” Justice Richard Cavanagh said in handing down his judgment.

“It would be surprising if the accused was there for so long beforehand … if his purpose was to start some sort of a fight with Mr O’Brien.”

Mr Gee, a Crown witness, told the court Johnson accused Mr O’Brien of sleeping with his partner before pulling out an unknown weapon.

Mr O’Brien died outside his Mayfield home. Picture: Supplied.

But in police body-worn camera footage played to the court, Johnson — who was arrested outside Mr O’Brien’s home minutes after the stabbing — told officers Mr Gee had attacked him.

“I am unable to make any positive finding as to precisely what occurred because Mr Gee is not a credible or reliable witness,” Justice Cavanagh said.

“The accused accepts that his conduct was not reasonable … he used excessive force.

“He is guilty of manslaughter but not of murder.”

Johnson will be sentenced at a later date.