The boy convicted of killing west Auckland dairy owner Arun Kumar has been sentenced to six years' imprisonment, with a minimum non-parole period of three years and three months.
A jury found the 14-year-old – who was facing a murder charge – guilty of manslaughter in June but decided his co-accused, a 13-year-old, was not guilty of manslaughter.
The teen, whose name is suppressed, appeared in the Auckland High Court today before Justice Graham Lang.
He sat scribbling on a pad with his head down, resting on a book on the table for much of the hearing as members of his family sat behind him.
His lawyer Maria Pecotic argued for leniency in sentencing, stressing his young age and vulnerable psychological state.
Since getting help after committing the crime he was improving at school, had better health and "learnt about himself and how to manage himself better," Ms Pecotic said.
"He has responded incredibly well to the treatment he has received to date."
She said a long jail term can be "crushing on young people" and stressed the ability youth have to rehabilitate.
Mr Kumar, 57, died after the older boy stabbed him three times, including once in the neck. The defence never disputed the fact the stabbing took place, but argued it was done in self-defence. They said the boy was unable to think properly during times of stress due to a brain injury suffered in a car accident as a child.
Justice Lang said he rejected "emphatically" claims the stabbing was carried out in self-defence but had to take into account the youth's brain injury.
The court heard the youth had trouble dealing with "complex situations" because of his vulnerable mental state, with Justice Lang saying he believed the complex situation began when Mr Kumar's wife threatened to call the police during the attempted robbery.
He said the teen reacted in an "impulsive, instinctual manner... with little or no thought of what you were about to do".
It was then only a "matter of luck" if a deadly blow was struck with the knife, Justice Lang said.
During the teen's trial the boy's brother testified they had grown up in a "drug house", and said the teen was addicted to synthetic cannabis by the age of 13. Justice Lang said "consumption of alcohol and drugs was a large factor" in the offending.
The court heard his mum tried to combat his synthetic cannabis addiction by giving him real cannabis instead.
"Your early childhood was turbulent in the extreme", Justice Lang told the teen.
Earlier this week the family of Mr Kumar said they would not be attending the sentencing as they believe "justice will never be done".
In a statement, the family said they "do not support the injustice and therefore there is no point in attending" the sentencing.
"Despite full CCTV footage, the use of weapons and witness testimony, our justice system came up with manslaughter for one and [the] other walked free," Mr Kumar's daughter Sheenal wrote, adding that the family felt like "idiots" going to court every day for the trial.
"During the trial we heard past history of injury and drug abuse taken into consideration. However, their criminal backgrounds and other recent criminal acts leading up to the 10th of June was hidden from the jury because the New Zealand justice system does not allow such offending to be taken into account.
"The concept of a 'fair trial' is indeed fair for the criminal, but what about the victims?"
In handing down his sentence Justice Lang said he had to consider the offender's young age and "vulnerable" mental state, while also putting a deterrent in place and considering the impact on the victim's family and the safety of the public.
"Offending like this has a ripple effect and wide circle of victims," said Justice Lang.
The teen will serve his time in a youth justice facility until he is old enough to be transferred to prison.
Speaking outside court, Ms Pecotic said the sentence did not come as a surprise but she remained hopeful her client would be released back into the community rather than being sent to prison.
"It's not an unexpected sentence that's been passed. The minimum non-parole period means that he's going to be around 16 years and nine months [old when he's eligible for parole]. I really hope that Child, Youth and Family service can put in place a plan that ensures that he isn't sent to prison, which I think would be incredibly detrimental to him."
She said it will take time for him to process his sentence.
"He didn't hear or understand a lot of what was happening in court, so he does need some time to think about it carefully and he'll do that – next week we'll take our time and go through it."