A man who claimed he only meant to damage his friend's new car has been jailed for at least 15 years and seven months for murdering him in a drive-by shooting.
Nine days before the Wollongong shooting, the victim had threatened Matthew Henry Spinks with a knife in his own home while under the delusion he had been sleeping with his partner.
Spinks, 37, was found guilty in February of murdering Nathan Costello, who was shot dead outside an Unanderra home in the early hours of Valentine's Day in 2018.
The 32-year-old was standing next to his parked car, near a friend who was doing minor repair work, while his long-term partner Melanie Hazell was sitting in the passenger seat.
After circling the area several times in a stolen black Mercedes, Spinks drove towards the house with the headlights off and the sun visors down.
He then produced a 12-gauge shotgun and fired two shots from the passenger window, killing Mr Costello who was hit with pellets in the neck, chin and chest.
In the NSW Supreme Court sitting in Wollongong, Justice Peter Hamill on Thursday jailed him for 20 years and 10 months with a non-parole period of 15 years and seven months.
As did 11 of the 12 jurors, the judge rejected Spinks' evidence that he had not intended to kill his friend of 15 years but only meant to damage his new car.
He testified to being angry when he saw the vehicle because he had helped Mr Costello avoid police when he previously crashed another car and received an insurance payout to buy the new one.
He also was upset about Mr Costello breaking into his house and threatening him with a knife nine days earlier.
"The deceased, as a result of schizophrenia, had a delusional belief he was sleeping with his partner," the judge said.
After the "callous" and premeditated killing, Spinks had walked his dog before going to a workers' club with a friend to establish some sort of false alibi.
Spinks had pleaded guilty to manslaughter on the basis of "an unlawful and dangerous act" with the mental element of his intention being the only issue at trial.
The judge referred to the devastating impact the murder had on Mr Costello's family and friends.
His mother said "she used to be scared of dying, now she was scared of living in a world without her son".
His partner, Ms Hazell "feels life has no meaning or purpose any more because she witnesses how easily it is taken away".
While the shooting was a very serious case of murder, the judge found a degree of mitigation flowed from a August 2017 incident, when Spinks was grabbed by a group of men outside his home and stabbed.
He suffered a serious wound to his abdomen and was left with increased levels of anxiety, paranoia and PTSD.
Spinks had become "emotionally unravelled" due to his condition and being confronted with the knife wielded by his mentally ill friend in his own home.
The judge found Spinks' use of the drug ice probably affected his judgment, it had not affected his intention to kill Mr Costello as was evidenced by his premeditation and planning.
Australian Associated Press
