A Canberra man who ambushed and shot dead one of his oldest friends behind the Hughes shops has been jailed for 28 years.
Kai Yuen, 28, was sentenced in the ACT Supreme Court on Friday for the murder of Brendan Scott Welsh, 28, in May 2010.
Mr Welsh was gunned down as he sat in his car behind the Hughes shops.
The killing was the culmination of a tit-for-tat dispute that began when Mr Welsh took a car used by Yuen's housemate to Melbourne.
Escalating threats and counter-threats were made through text messages, with Yuen warning the victim to ''arm up'', and that he was ''playing a different game''.
Their argument boiled over when the window of Yuen's work van was smashed.
Yuen donned a disguise, picked up his double-barrelled shotgun, and spent hours trying to confront Mr Welsh across the city.
Mr Welsh was eventually lured to the shops on the pretence of a drug deal in the early hours of May 10. He was ambushed by a shotgun-wielding Yuen, who had been hiding behind a nearby wall.
Two shotgun rounds were fired into the vehicle and Mr Welsh was fatally wounded in the chest.
Yuen was arrested in August 2010 and in February this year became the first person in more than 15 years to plead guilty to murder in the ACT.
But he disputed the facts of the murder, claiming he had only meant to bash Mr Welsh, and had fired the fatal shots by accident after the shotgun became unbalanced in his hands.
The court also sentenced Yuen over a prison bashing last year that left an inmate slumped in a pool of blood and requiring five plates in his face.
CCTV vision shows Yuen in a prison common area, taking his shirt off and limbering up, before picking up a vacuum cleaner pole and walking up behind a seated prisoner.
He hit him repeatedly in the back of the head, and
then in the face, leaving the victim with serious injuries.
Yuen said the other inmate was making threats towards him, and that he was ''backed into a corner''.
Justice Hilary Penfold jailed Yuen for 21½ years for the murder and 6½ years for the bashing, backdated to take into account time spent in custody.
He will not be eligible for parole until 2030.
In handing down her sentence, Justice Penfold said both attacks were ''cowardly'', because they involved dangerous weapons and unsuspecting victims.
But she found the murder was not in the worst category of the offence and did not justify the life sentence sought by prosecutors.
Friends and family of Mr Welsh were in court on Friday, and some wept as Justice Penfold handed down the sentence.
Mr Welsh's former partner Stephanie Turner - who was pregnant with his child when the murder occurred - said the sentence was fair. ''Justice has been done and that's all we can ask,'' Ms Turner said.
''He was an awesome person, he might have done wrong in his life but he loved me, I loved him, and we were close. He didn't deserve this,'' she said.
Mr Welsh was killed one day after Mother's Day, and just three weeks before he and Ms Turner were to marry.
Her daughter will grow up without ever having known her father.
''She'll be shown all the letters and photos with the family and the other children, and she'll know who he was through all of that,'' Ms Turner said.
Mr Welsh also had three other children with a former partner, who is also deceased.
In a written statement to Fairfax Media, his mother Karen Welsh and sister Sally Hughes said they were pleased with the sentence, and that ''justice has been served for Brendan and his children''.
''Brendan can now rest in peace and his family unit can commence moving forward with their lives,'' they wrote.
''We'd like to take this opportunity to thank the team that have worked for the past three years to get this result. In particular members of the AFP and DPP. The work they have done and ongoing support they have provided has blown us away.
''We love you Brendan, you'll always be in our hearts.''
Yuen read a statement out to the court last month, in which he said he was sorry for what he had done.
He said the fact he had taken a father away from four children ''haunts me every day of my life, and will continue to do so until the end of my life''.
''I want every member of Brendan's family to know I am sorry, with every bone in my body, I'm sorry,'' he said.
Yuen had told the court that he wished to atone for his wrongs by rehabilitating himself and addressing his anger issues, saying he didn't want to hate himself any more.
''I murdered Brendan Welsh but I refuse to believe I'm a murderer,'' he said.
On Friday, Justice Penfold urged Yuen to follow through with those aims.
She said she suspected it would be all too easy to abandon efforts to change his ways and become a ''prison hard man''.
''I urge you, however, to hold to your goals,'' Justice Penfold said.
She said Yuen should become a mentor to younger prisoners, and help them avoid the mistakes he had made.
Justice Penfold said there was no guarantee he would get parole in 2030 if he behaved badly and committed more offences behind bars.