Supplied: Tasmania Police
)A 19-year-old Tasmanian boy shot and stabbed to death by his friends in Launceston in 2019 was murdered with his own gun, a court has heard.
The Supreme Court in Launceston on Friday heard Billy Ray Waters possessed a 12-gauge single-barrel shotgun, just months before his death.
The gun had been taken off him by an older man, who was concerned Mr Waters would use it.
The court heard that man then gave it to Christopher Leigh Brown, 34, of Launceston, to "protect" Mr Waters.
Brown has confessed he then sold on the gun to then-17-year-old William Adair Rothwell for $500 on July 31, 2019.
Rothwell and Jacob Michael Brennan used the gun just days later to murder Mr Waters.
Rothwell and Brennan are each serving 26-year jail sentences after they pleaded guilty to the murder in February last year.
Justice Robert Pearce has allowed that the teenagers be publicly named due to the interest in the murder case and the fact it was a "heinous crime".
The new evidence was revealed as part of Mr Brown's sentencing submission for his role in the murder.
The court heard Brown had initially been co-accused of Mr Waters' murder, but prosecutors dropped the charge earlier this month and he instead pleaded guilty to trafficking a controlled substance, dealing in firearms while not the holder of a firearms licence and being an accessory after the fact of Mr Waters' murder.
Accused approached for firearm purchase
During the sentencing submissions, Tasmania's Deputy Director of Public Prosecutions Linda Mason SC said Brown had been supplying cannabis to Rothwell throughout 2019.
Rothwell was then onselling the cannabis to other teenagers at Launceston's Royal Park, the court heard.
Ms Mason said Brown and Rothwell held a "grievance" against Mr Waters as they believed he had been stealing cannabis from them.
She said Brown confronted Rothwell about that in July 2019, and said: "Someone should teach Mr Waters a lesson. It wouldn't be hard to get someone to tap him, would it?"
The court heard Rothwell then told Brown "he wanted to get even" with Mr Waters.
The court heard later that month on July 31, Rothwell approached Brown wanting to buy a 12-gauge single barrel shotgun off him.
"The accused told police he had no idea why William Rothwell wanted it, but he knew he had a fascination with firearms," Ms Mason said.
ABC News: Laura Beavis
)'An incredibly stupid thing to do'
Ms Mason told the court the state accepted that Brown did not sell the gun knowing it would be used to kill Mr Waters.
"He was recklessly indifferent to what was going to happen," Ms Mason told the court.
"He at least knew he had a 17-year-old drug user that was ruminating about harming people.
"It's the state's position that the accused would have realised when he handed over the gun that someone might have got hurt … but that probably didn't crystallise until after [the murder]."
The court heard that Rothwell told police in an interview that Brown had instigated the murder, but Ms Mason said the state had accepted that was not the case.
"He did not intentionally counsel Mr Rothwell to harm Mr Waters with the firearm," Ms Mason said.
Justice Michael Brett, who was convening the sentencing submissions, agreed the decision by Brown to sell the firearm to a teenage drug dealer was "an incredibly stupid thing to do".
Brown's defence counsel Fran McCracken told the court her client had sold the gun to Mr Rothwell for $500 with the understanding it would be used in other crimes, like burglaries.
"He had no expectation that the firearm would be used to hurt or kill Mr Waters," Ms McCracken said.
Ms McCracken said her client's comments to Mr Rothwell earlier that month that someone should "tap" Mr Waters, were said is a social setting with others present and were not meant literally.
"He was talking as hyperbole," Ms McCracken said
The court heard Brown had pleaded guilty to being an accessory after the fact of Mr Waters murder as he had helped the two youths dispose of the firearm used in the murder and had help returned a house key of Mr Waters to his housemates
"He's very remorseful for the part he has played in this" Ms McCracken said.
She said her client only knew Rothwell and did not know Brennan.
Brown has been remanded in custody and will be sentenced on March 31.
