A judge has described a murder victim's simple decision to cross a road as a "catastrophic example of a sliding doors moment".
The killer, who was 17 at the time of the fatal bashing, is set to be released from jail late this year after committing an armed robbery in 2022.
Liang Zhao was brutally killed with a machete on the side of a road in Braddon, 2011, by the teenager and his co-offender, Taylor Schmidt.
The Canberra Times has chosen to refer to the man's role in the death of Mr Zhao and therefore cannot name him because he was a child at the time.
After more than 10 years in jail he was released, but five months later he was back behind bars after committing the armed robbery.
In June 2022, the man, toting a firearm, was involved in beating a woman over an alleged debt.
The offender and three other robbers entered the woman's home, where she was repeatedly punched, had a handful of hair ripped from her scalp, and one of her front teeth pushed back.
They stole her phone and keys.
In the ACT Supreme Court on Friday, Justice Verity McWilliam resentenced the man for the murder, handing down an 18-year jail term backdated to 2011.
This will be suspended after 13 years, upon the man entering into a good behavior order for the rest of the sentence.
For aggravated robbery he received a backdated two-year-and-four-month prison sentence.
As a result he will eligible for release from jail in November 2024.
When he is free, the now 30-year-old man will have spent almost half his life behind bars.
On Friday, Justice McWilliam said the fatal attack on Mr Zhao was "entirely unprovoked".
More than a decade ago, Mr Zhao, 27, was walking along Northbourne Avenue in the hope of being picked up by his mother, after arriving at the Jolimont Centre on a bus from Melbourne.
In what Justice McWilliam described as "a catastrophic example of a sliding doors moment", Mr Zhao had crossed to the Braddon side of the busy road.
The 17-year-old and Schmidt were "drug- and alcohol-fuelled" and planning a robbery.
What happened next "creates an excruciating sadness for the victim in the manner and fact of his death", Justice McWilliam said.
Armed with a machete and a baseball bat the pair attacked Mr Zhao, inflicting fatal wounds.
They stole $21 in cash and his mobile phone.
On Friday, Justice McWilliam said the robber was "obviously attempting to take positive steps".
She stated a report author found the man was "a highly intelligent individual who has great potential in whatever field he applies himself".
Justice McWilliam said the man "quickly became lost" and relapsed into methamphetamine use when he was released from jail in 2022.
The judge found deterrence was "likely to be achieved by the carrot and not the stick".
Justice McWilliam said a sentence with strong supports in the community would "turn this offender away from anti-social behaviour".
