Wyong gunman Bradley Jason Mark White found guilty of murder over shooting of Byron Tonks

He was angry, irrational and, according to his defence barrister, "off his rocker" and "totally crazy".

He may have been suffering a mental health or cognitive impairment, but White, now 42, knew what he was doing over that hour-long shooting rampage in Cutler Drive on March 17, 2020, was wrong, a jury found on Thursday, convicting White of murder and six other serious shooting charges.

White will face a sentence hearing in December and faces decades behind bars for what was one of the most horrific public shooting incidents in NSW in recent memory.

White was angry over a long-running and "ridiculous" grievance he had with a young neighbour over the road in Cutler Drive when he twice set fire to a car and then began firing two guns from his verandah and inside his house.

He shot at people in the street, striking one man in the shoulder and a woman in the back, fired upon responding police and pumped bullets into eight cars and a number of houses across the road, next door and behind his property.

At one point during the relentless barrage of bullets, Byron Tonks, who had driven to a house in Cutler Drive to help, screamed out from the front room: "I've been hit".

Ultimately, as Mr White continued shooting into the house, police had to remove the three injured people through the backyard.

Byron Tonks was treated by paramedics but died at the scene.

White did not deny firing the rifles into the homes and shooting the three people, including Mr Tonks, but pleaded not guilty to murder and six other charges and raised a defence of mental health impairment or cognitive impairment, which he said impacted his ability to know what he was doing was wrong.

But after listening to expert evidence, police interviews with White, submissions from the prosecution and defence and deliberating for less than a day, the jury returned about midday on Thursday and found White guilty of all charges.

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