A man wielding two large knives stabbed to death his half-sister's partner as he sat in his car in broad daylight following a long-running feud, a court has heard.
Crown prosecutor John Stanhope told a Newcastle Supreme Court jury on Tuesday Justin Fuller was in December 2018 armed with two 45-centimetre machetes when he leaned into the driver's side window and stabbed Guy McCulloch four times.
Mr McCulloch, 50, bled to death after one deep stab wound penetrated his liver.
Fuller, 34, has pleaded not guilty to murdering Mr McCulloch in Beach Street, Belmont South but guilty to the lesser charge of manslaughter.
Mr Stanhope said there was no issue Fuller had killed Mr McCulloch, who went by the nickname "Wink", but the jury had to decide if he had intended to kill or cause serious injury.
Defence barrister Winston Terracini SC told the jury Fuller's trial would also look at issues involving self-defence and provocation.
Mr Terracini said there had been a long-standing toxic relationship between Fuller and his half-sister Kristy Duley, the de facto partner of Mr McCulloch.
The defence barrister said the animosity between the pair extended to Facebook messages posted by Ms Duley targeting Fuller where she expressed feelings of hatred.
Mr Terracini claimed Ms Duley had also posted Facebook messages declaring it would be a great birthday present or Mother's Day gift if their mother was killed by a brown snake.
In his opening address to the jury, Mr Stanhope said the fatal stabbing occurred after Fuller and partner Narelle Abercrombie drove past Ms Duley and Mr McCulloch parked in Beach Street.
Ms Duley called out "tick tock" to the pair and Ms Abercrombie gave her the finger.
Fuller later approached Mr McCulloch's Nissan 4WD on foot and argued with his sister and her de facto before Mr McCulloch twice reversed his car into Ms Abercrombie's Holden Commodore, stopped directly behind him.
Mr Stanhope said Fuller then went to his home and grabbed a backpack with two large knives before walking back to the Nissan where Mr McCulloch and Ms Duley were still seated.
As Fuller approached, one of Mr McCulloch's friends saw him and called out: "He's got knives, go."
But before Mr McCulloch could drive away, Fuller reached through the driver's side window and stabbed him with the machetes.
The prosecutor said Mr McCulloch suffered four stab wounds, went into cardiac arrest and died at 2.42pm. He said what killed him was the penetrating stab wound to the liver which had caused him to bleed to death.
The trial before Justice Richard Cavanagh continues.