A teenager acquitted of a Canberra skatepark killing invaded the home of a witness and attacked their mother soon after being released from jail.
"I broke into a snitch's house and punched his mum in the face," the teenager later told a psychologist, according to a report tendered to the ACT Supreme Court on Thursday.
The 18-year-old man, who cannot be named because he was a child at the time of his crimes, faced court via audio-visual link from the Bimberi Youth Justice Centre.
He had previously pleaded guilty to two counts of assault occasioning actual bodily harm, as well as single charges of burglary, property damage and minor theft.
The teenager had also admitted a reprisal charge, which was later dropped after he asked to withdraw his guilty plea.
His latest wave of offending began in August 2022, a little more than a week after he was sentenced to a backdated jail term for recklessly inflicting grievous bodily harm.
The teenager committed that crime during a wild brawl at the Weston Creek skatepark, in which he seriously injured a 16-year-old rival combatant by stabbing him in the back.
He was also accused of fatally knifing that victim's older cousin, but a jury found him not guilty of murder.
Fresh from a stint in Bimberi in relation to the brawl, the offender went to a Canberra gym to lift weights.
While there, he tried to shake the hand of a former friend he knew from school.
He did not not take kindly to his invitation being rejected, punching the young man twice in the face.
The victim was left with a swollen cheek and a bleeding nose as a result.
The following month, the offender broke into the home of another former friend in Canberra's south.
This old friend, who had also participated in the fatal skatepark fight, had been a witness for the prosecution during the offender's murder trial.
On the day of the intrusion, the teenager smashed a window to gain entry to the witness' home and started ransacking his bedroom.
When the witness' mother confronted him, he punched her in the face and threatened to stab her.
The offender eventually left, stealing one of the witness' jackets and kicking his car as he departed.
He was arrested the following day and was returned to Bimberi, where he has been remanded in custody ever since.
On Thursday, the 18-year-old gave evidence and claimed the gym assault victim had been "aggressive" towards him.
He spoke of subsequently burgling the witness' home because he had no money and was "frustrated".
Asked why he chose the home of someone who had testified in his murder trial, he replied: "I thought if I was gonna rob anyone, it should be someone I know, not someone who hasn't done anything to me."
The court heard he had not expressed remorse for this incident when speaking to psychologist Leesa Morris, telling her the witness had "dogged" him.
"I had a plan but he wasn't home, so I just took his shit," the offender told Ms Morris.
In his evidence on Thursday, the teenager said his plan had been to steal the witness' car.
He told the court he now wished neither of the latest incidents had happened, claiming he was remorseful in relation to both of them.
Chief Justice Lucy McCallum remarked that there seemed to have been a "catastrophic failure of supervision" last time the offender was released from custody.
Defence lawyer Peter Bevan told the court there was a better plan in place this time, with the 18-year-old set to live with his parents upon his release.
Mr Bevan also noted the youngster required open heart surgery, ideally before the end of June.
He asked Chief Justice McCallum to structure a sentence accordingly.
Prosecutor Morgan Howe agreed the imperative of the surgery was an exceptional circumstance.
Chief Justice McCallum indicated she would sentence the offender next Wednesday.
