The ACT Supreme Court has heard the man who pleaded guilty to the shooting murder of Canberra man Glenn Walewicz, said: "I love doing crime" and it "makes you feel high on life".
Mr Walewicz, 48, was shot dead at his Phillip unit in June 2021, in a case of "mistaken identity".
The agreed facts state the shooter, 20, and two other males intended to carry out a home invasion, to steal money and drugs but went to the wrong unit.
Mr Walewicz was shot in the neck and died shortly after.
The man who pleaded guilty to shooting Mr Walewicz cannot be named as he was a minor at the time.
The court heard excerpts from a Child and Youth Protection Services Pre-Sentence Report that he told a youth worker he couldn't imagine his life free of crime and loved the adrenaline and control he felt when he robbed someone.
"I love doing crime, being in the room telling them to give me the money.
"It makes you feel high on life."
The report showed the shooter had experienced a level of trauma, adversity and instability throughout his life.
It said he first came to the attention of Child and Youth Protection Services in 2007 and there had been a total of 32 Child Concern reports around physical abuse and his exposure to family violence.
Psychiatrist Dr Jaques Claassen told the court the man had developed a series of psychiatric conditions including PTSD, borderline personality disorder and social personality disorder.
He said the psychiatric conditions contributed to the offence as it would have "adversely impacted his ability to clear, rational and sound decision making", but maintained it was not the cause of the crime.
The court also heard a victim impact statement from Mr Walewicz's widow, Eileen Walewicz, who said his death has left her feeling like she's "treading water with nowhere to go."
Mrs Walewicz told the court she was in hospital recovering from major spinal surgery when she found out the news.
She said she is heartbroken and has "a rage inside" over his death.
"There are days when I stay in bed all day and don't see anyone," she said.
"I think of Glenn every day and feel an overwhelming sadness for the loss of someone I love."
24-year-old Gary Taylor was sentenced to more than 10 years jail over the crime last year, while charges against a 13-year-old boy were dropped in 2022.