A meth-fuelled tradie, who ran down a workmate, severing his leg, and violently attacked him with a demolition hammer, will spend at least 12 years behind bars.
Despite the carnage, Matthew William Lawson later said he was devastated to learn his victim had survived, and vowed to go back and finish the job.
The 26-year-old had used methylamphetamine, drunk a bottle of whiskey and not slept for a week when he attacked Trae Black at a Perth worksite in July 2024.
The assault started when Lawson swung a hammer at Mr Black's head, which missed his intended target, Western Australia's Supreme Court was told during his sentencing.
When Mr Black fled into nearby bushland, Lawson, who was in the grip of an acute psychotic episode, pursued him on foot and then in his car before mowing him down.
"You had to drive your car off the highway and into bushland over a steep bank to deliberately hit Mr Black," Justice Natalie Whitby said.
"After striking Mr Black with your car and fracturing his pelvis and severing his leg, you got out of your car and repeatedly struck Mr Black to the head with a demolition hammer, a very dangerous weapon - fracturing his skull."
When police arrested Lawson on suspicion of assault, he responded to officers, saying: "Nah. Murder".
"If he's not dead, I'm going to go back and kill him," the court heard he also told officers.
Lawson, who was spending $250 a day on drugs, later said his motive for assaulting Mr Black was that he believed the methylamphetamine he used had been "chopped" and he feared it was going to kill him.
Mr Black lost his right leg and suffered fractures to his pelvis, skull, jaw, cheek and eye socket and a bleed on the brain, spending 11 days in a coma.
He was unable to walk for eight months and now has a prosthetic leg, but he is unable to work and suffers recurring nightmares and flashbacks.
Justice Whitby said Lawson's attack on Mr Black was premeditated and sustained, and that he did not try to help him after the attack.
"Mr Black was very vulnerable at the time you hit him in the head with the hammer - he was laying on the ground with a severed leg and broken pelvis," she said.
"Your offending was very violent against a defenceless victim."
Lawson was sentenced on Monday to 14 years' imprisonment, eligible for parole after 12 years, for attempting to murder Mr Black.
