A masked gunman has claimed he wanted to "scare" his victim, who he alleges stole a $10,000 electric bicycle.
Mariusz Ergland Nurzynski, who is turning 60 in less than two weeks, has pleaded guilty to discharging a firearm and endangering life, and unauthorised manufacture of firearms.
Agreed facts state in August 2023, in Phillip, the victim noticed a man, who was wearing a face covering, standing behind him.
The victim chased the man up a nearby alleyway, before seeing the barrel of a homemade firearm pointing at his head, and retreating to his car.
The victim then drove his Mitsubishi Triton towards the disguised figure and heard a loud "boof", which he believed to be a gunshot.
Police later found an "elongated cylindrical hole" near the passenger's side door handle.
The next day the masked man, identified as Nurzynski, told officers he tested the homemade firearm at drains near Woden Cemetery.
He said he knew how to make the gun "on account of the general principles of physical inertia" and had constructed it out of "materials he'd picked up over the years".
Giving evidence in the ACT Supreme Court on Thursday, Nurzynski said when he test fired the gun "it shocked me".
Nurzynski said despite a "wonderful childhood" he started living on the streets at 17, when "he met marijuana".
He then started taking heroin and ice, and for 30 years helped run a soup kitchen.
Nurzynski claimed the victim had stolen his $10,000 electric bicycle, purchased with money he received when his mother died.
"I wanted to scare this guy one more time, [I thought] maybe he'll give back my bike," Nurzynski told the court.
He claimed he went to police four times to report the stolen bike, but "they laughed at me".
Nurzynski also stated the victim had tried to hit him with his vehicle.
"I was discharging [the gun] to stop this car hitting me, there wasn't an aiming factor in this."
The almost 60-year-old stated he now "felt fantastic" after being drug free while in jail on remand for the past seven months.
"I don't want to break the law anymore," he said while crying.
In response to questions from a prosecutor, Nurzynski said he was on "crumby ice" at the time of the crimes.
Legal Aid lawyer Nathan Deakes urged the court to consider a sentence to be served in the community, rather than behind bars.
"He wants the opportunity to attend soccer matches, family dinners ... and anything else he is called upon," Mr Deakes said.
A prosecutor argued for full time imprisonment, saying Nurzynski's abstinence from drugs occurred "in a controlled environment without the pressures that are faced by people in the community".
Justice Verity McWilliam ordered Nurzynski undertake an assessment for a Drug and Alcohol Treatment Order.
"Sometimes it takes people 60 years on the earth to realise a drug free life is the best freedom you can have," Justice McWilliam said.
Nurzynski's sentence will be handed down at a later date.