A Victorian man shot his rival in the head after being called a "putrid dog" in a Facebook fight.
Craig Williams held police at bay for hours in a stand-off after killing 31-year-old Joshua DiPietro through a car window on the Mornington Peninsula in September 2017.
The pair had engaged in a war of words before Mr DiPietro rolled up to the Rosebud home Williams shared with his mother on Father's Day.
Williams was ready with a rifle and his half-brother John Godfrey with a handgun.
"Put that away. Don't be silly," Mr DiPietro said before Williams fired twice into the car.
Afterwards Williams destroyed the home's CCTV box with a hammer and threw it off a bridge.
He laughed at a news story about Mr DiPietro's death, but said he wished he hadn't done it.
The next day, he holed himself up inside and engaged in a 10-hour stand-off with police, telling them the people he hurt "f***ing deserve it" and "ask my f***ing mum".
Tracey Godfrey tried to help her sons cover up the crime, but it didn't work.
Williams, now 32, has pleaded guilty to manslaughter. His barrister says the man didn't mean to kill Mr DiPietro, but wanted to scare him off.
"Mr Williams had a genuine belief that Mr DiPietro was going to come around and shoot him and Mr DiPietro said as much," barrister Michael McGrath told the Supreme Court of Victoria on Monday.
Godfrey, 27, admitted to reckless conduct endangering serious injury. He didn't fire at the car, but helped dispose of evidence.
Mr DiPietro's mother said the cowardly killing remained incomprehensible.
"It's impossible for others to see into the heart of a grieving parent," Fiona DiPietro told the court.
"If you could see inside, you could see a hole right in the centre of the heart."
Williams apologised to the family through his lawyer.
"It may be cold comfort hearing it from me," Mr McGrath said.
The killer was using drugs including ice and cannabis at the time.
He was also on a community correction order, and had a violent history including an attack on a 16-year-old boy with a machete and firing a gun at a vehicle.
Godfrey was a socially isolated loner and hadn't been in trouble with the law, his barrister John Saunders said.
Both men had mental health problems and difficult backgrounds, the court was told.
They remain in custody and will be sentenced at a later date.
Tracey Godfrey earlier this year avoided jail and was ordered to be of good behaviour for 18 months after admitting to helping clean up the crime scene and cover for her children.
Her ex-partner, David Lyons, was jailed in 2019 for his role in the shooting, which included removing ammunition from the scene and intimidating a witness.
Australian Associated Press
