The New Zealand Herald is looking back at the crime stories that shook the country. This article was originally published in August 2015.
One piece of evidence seems to sum up the disturbing childhood of the boy who killed Arun Kumar.
The 13-year-old stabbed the West Auckland dairy owner with a knife - once, twice, the third time fatally in the neck - during a robbery attempt with his 12-year-old friend that went badly wrong.
Charged with murder and manslaughter respectively, the pair sat quietly and coloured in pictures as their trial in the High Court at Auckland started.
Representing the slightly older boy, defence lawyer Maria Pecotic called his brother as a witness to give the jury an insight into their lives growing up.
Their mother was selling synthetic cannabis from her home on Great North Rd, where her son lived and his friends often stayed the night to get stoned.
Addicted to synthetic cannabis, the boy was often a "zombie" according to his brother.
Pecotic: Did anybody do anything to help [him] with his addiction?
Brother: My mum done something to help him with his addiction.
Pecotic: What was that?
Brother: She was giving him marijuana.
The point was not lost on the trial judge, Justice Graham Lang, who specifically referred to the exchange in sentencing the boy on his manslaughter conviction.
The judge said his early childhood was "turbulent in the extreme" and helped explain why he was acquitted of murder, but found guilty of the lesser charge.
The jury were not convinced beyond reasonable doubt that the teenager intended to cause "really serious bodily harm" to Mr Kumar. "I am satisfied that you reacted in an impulsive and instinctive way with little or no thought for the consequences of what you were about to do," Justice Lang said.
The verdict and sentence of six years in prison outraged the victim's family. They believe the justice system failed Mr Kumar, left to die on the floor of his own shop.
But there are others who believe the boy was failed by his family and the system, even before he was born in January 2001.
His mother drank alcohol and consumed drugs heavily during her pregnancy with him, her sixth child. He was raised in a home of fear, with 10 notifications to CYF of violence between his parents between 1999 and 2004.
That's if his parents were home. A neighbour alerted CYF that the boy, just 3, and a younger sibling were left in the care of their sisters, aged 12 and 13. The older children, who were not enrolled in school, then left the pre-schoolers home alone. "Parents rarely seen," according to the CYF file, and the situation for the children was "dangerous".
In 2005, the mother left all the children with a relative and disappeared, failing to return within three weeks. CYF were told she was using P and heroin daily, "shooting up" in front of the children, and that gang members raided the family home.
At a meeting, CYF established that the boy and his siblings needed care and protection, but the children were returned to their mother because she promised to engage with community groups.
The older brother told the jury he could remember living in 10 different houses. He said the children were not allowed to go to the doctor unless "we were dying" and their sister - who was just a few years older - took care of them because their parents were always "doing drugs and stuff".
"Drugs was there when we woke up, it was there when we were having breakfast, it was there, like before lunch, during lunch, after lunch and dinner."
By the count of Dr Valerie McGinn, a neuropsychologist who works with young people with learning and behaviour problems at Auckland City Hospital, there were about 20 notifications to CYF.
"They painted a picture of a life of neglect and a lot of disruptions," she told the jury during the murder trial.
A Family Group Conference in May identified the teen as an "at-risk" child who should be removed from the home. But his social worker was unable to find him and his file was shifted between CYF branches. A month later, Mr Kumar was dead.
A spokeswoman for CYF declined to answer questions but confirmed the Office of the Chief Social Worker was conducting a review expected to take several months.
"While neither of the boys [standing trial] was ever in Child, Youth and Family care we need to understand if there was more that we and other agencies could have done."
Considered an expert in her field, Dr McGinn previously gave evidence at the Privy Council in London about how Teina Pora's mental development was impaired by Foetal Alcohol Spectrum Disorder.
She spent time with the boy and interviewed his mother, conducted tests, and reviewed his "quite extensive" history with CYF, as well as education and medical records.
One piece of information, recorded on April 12, 2009, immediately caught her attention.
The 8-year-old boy was struck by a car on a pedestrian crossing and flung 4m in the air. He was knocked out, suffered a seizure, fractured skull and a brain-bleed. Four days later, the youngster was discharged from Starship Hospital. An occupational therapist established he suffered a "traumatic" brain injury and wrote a referral letter to ACC for rehabilitation.
Despite this, the boy never received treatment.
"There were no further records, which either means rehabilitation wasn't offered - which I find hard to believe - or else for some reason, he was not provided with medical follow-up because perhaps the family didn't attend the appointments," Dr McGinn said.
An ACC spokeswoman said if there were insufficient telephone contact details on the referral, ACC would write a letter to ask the patient's family to contact ACC directly to arrange necessary treatment and support.
"If we never heard from them or any other treating provider, such as an occupational therapist, GP, or physio, we'd likely assume nothing was needed."
Because the accident happened during the Easter holiday break, the boy did not return to school for two weeks. Dr McGinn said an adult who suffered the same injuries would not return to work for two years and then only on a part-time basis.
Children who suffer traumatic brain injury symptoms feel "dreadful", suffer blinding headaches and cannot handle any stimulation or noise.
"They need a really quiet peaceful time and if they don't get that, what happens is the brain becomes overloaded and basically shuts itself down and this is seen and experienced as what we call cognitive fatigue ... glassy-eyed and sleepy," Dr McGinn told the jury.
"From my experience, they become extremely irritable ... if you didn't know they had brain damage, you'd think they were being very naughty but they're not being naughty, they're just - their brain can't regulate and it really needs a rest."
Before being hit by the car, he had no learning or behaviour problems recorded on his file. Six months later, his school principal referred him to the youth mental health clinic, the Kari Centre, with "serious concerns".
"[He] teases others. If he feels he has been slighted in any way he will attack them without remorse. Recently he has been demonstrating self-harm behaviour," the principal wrote.
"Last week he locked himself in the toilet, smashed the toilet seat and then began to bang his head on the toilet cubicle wall. He often gives up on his school work or says he can't do it."
The boy was recorded as banging his head against the classroom wall and his teacher asked him why. the boy replied: "Because I just don't want to feel any more". On another occasion, he told a teacher he wanted to kill himself. He was reported to become easily frustrated and then verbally intimidating and physically aggressive towards other children.
"So this was about six months after his traumatic brain injury," said Dr McGinn. "This is what happens if a child has a traumatic brain injury and they get put back into an environment ... nobody could cope with."
Despite this, the Kari Centre declined the referral and did not pick up on the fact he had suffered a head injury. "That was despite the fact they would have access to all his medical records where it's clearly documented that he had a severe traumatic brain injury, so I don't know what went wrong there."
The Kari Centre noted they were also unable to find his social worker at CYF, or her supervisor. A spokesman for the Auckland DHB declined to comment because of an "ethical and legal duty" to protect his privacy.
By the time the boy started high school in West Auckland last year, he had been enrolled in eight schools in as many years.
Dr McGinn said each school might not have been aware of his brain injury. "It may have been that by the time they realised, he was on to the next school."
He was truanting regularly in his first year of college. By June 2014, the month he killed Mr Kumar, he had attended just 52 half days out of 148 and the school social worker referred him to the truancy arm of the Waipareira Trust.
Chief executive John Tamihere said Waipareira had 10 weeks with the teen until he was stood down by the school on May 28, for "unsafe behaviour", so they could no longer be involved.
Of the 40 days he was supposed to be at Waipareira, he missed 16.
Mr Tamihere said the help the 13-year-old needed was beyond what Waipareira could provide.
"Some interventions are quite easy, some interventions - like this kid - are very difficult. A normal person looking at this would scratch their head and say 'Jesus, there's no hope for this kid'. A kid like this needed resources we didn't have."
Before the suspension from school ended the boy's contact with Waipareira, a referral was made to RockOn - Reduce Our Community Kids Offending Now - an inter-agency group with representatives from local schools, police, the Ministry of Education and CYF, among others.
It's not known what the outcome was. The last note on Waipareira's file shows the boy was referred to a counsellor for anger issues after being suspended from school in May.
Around the same time, CYF didn't remove him from his mother's care so he continued to live in squalor and addiction at her doss house on Great North Rd.
The boy got stoned on synthetics with some other teenagers at the house, into the early hours of June 14, 2013, before he was woken by another boy who wanted to steal shoes from a store in Henderson. They were egged on by an older boy and left the house carrying a metal pole and a bag, with a knife inside.
The pair didn't break into West City Shoes but crossed the road to the Railside Dairy. The older boy went inside twice to "scope out the lie of the land", according to Justice Lang, then approached the shopkeeper, Arun Kumar. The other boy stood at the doorway holding the pole.
One of the boys called out, "Give us the money," although the would-be killer did not present the knife or make overtly threatening gestures at first.
There was no suggestion that Mr Kumar thought he was under severe threat, said Justice Lang, and Mr Kumar did not use the panic button. Instead he adopted the ploy he and his wife had devised to deal with troublemakers, which was to bring out a phone to show them the police were about to be called.
By this stage, the teen was leaning against the counter and had yet to pull out the knife. Mrs Kumar then emerged from the back of the shop holding the phone.
"At that point, things changed dramatically," said Justice Lang. He brandished the knife at Mrs Kumar and knocked the phone out of her hands.
Mr Kumar began walking out from behind the counter, but the teen turned his attention to him and drove him back into a corner with the knife.
The shopkeeper picked up a silver pole on the ground and raised it towards him, who responded with three blows of the knife. The third was fatal. The entire episode was caught on camera.
Justice Lang "emphatically" rejected any suggestion of self-defence, but the brain injury the boy suffered when he was 8 became a key part of his legal defence to the murder charge.
Dr McGinn described the lack of rehabilitation following the traumatic brain injury as "medical neglect". Combined with his dysfunctional home life, she said, his recovery was significantly disadvantaged.
"We know [he] ... had exposure to drug culture, he began to use drugs himself from quite a young age ... Sometimes young people who have a brain injury may start to use drugs partly because they're impulsive and they don't think through, but also because they don't feel that well and they kind of self medicate.
"He didn't get medical treatment and he did slip into addictions and he is predisposed to addictions because it runs in his family."
Despite this, he had been a "bright boy" with a normal IQ and slightly below average scores in reading, writing, spelling and mathematics.
Specialist tests showed the brain injury meant he is now slow to process information, particularly in complex situations when "overloaded" with stimulation. This means he had a limited ability to make appropriate decisions and acted impulsively, said Dr McGinn - like lashing out with a knife at Mr Kumar when the robbery went wrong.
It seems the jury agreed and the teenager was convicted of manslaughter, not murder.
Now 14, he walked out of court carrying a Harry Potter book after being sentenced to six years in prison. Having served some time in a youth justice facility awaiting trial, he is eligible for parole by the time he is 16 years and 9 months.
Speaking to media outside the High Court, his lawyer, Ms Pecotic, said her client's family "certainly did play a big part in where he is now".
"It's a family life that none of us would want a young person to live through. It's an absolute tragedy."
An experienced advocate in the Youth Court, Ms Pecotic told the Weekend Herald he was not a hardened criminal, that he lacked the "toughness" of many of her other clients.
She agreed with the principle of the CYF Act - to try to keep a family unit together as much as possible - but in this case believed he should have been taken from his mother's care. "These were children that CYF knew were at risk. They should have been removed."
Drugs and alcohol, violence, criminal influences, unemployment, little food and clothing in the house, no medical treatment, moving schools, moving houses, truancy - all the warning signs were there, said Ms Pecotic.
"There are a lot of things about him I find incredibly sad. He was only 9 and making suicidal comments. Most normal people would hear that and say: 'This is not how a 9-year-old behaves. What is going on in this child's life?' And look into it," said Ms Pecotic.
"This case is the epitome of neglect and the failure of the welfare state. And at what cost? Two lives."
And at the beginning of it all, Ms Pecotic said there was a "mother who's broken", born into the dysfunction of her own criminal parents and who fled the violence of her son's father when he was a toddler.
The Weekend Herald has obtained the mother's criminal history of 50 convictions dating back to 1991 - as well as nine aliases - including a five-month stint in prison when her son was 5.
Her rap sheet includes shoplifting, stealing cars, receiving stolen property, false cheques, burglary, common assault, wilful damage, possession of methamphetamine utensils, resisting police, cultivating cannabis, wilful trespass, drink driving, stealing bank cards, and breach of bail.
Shortly after her son was charged with the murder of Mr Kumar, the police again raided her home, which was known as a place to hang out and consume drugs.
They found pipes, home-made and commercial, as well as bongs made from plastic bottles used to smoke cannabis, in nearly every room of the house.
Cellphone records revealed text messages in which she offered to supply methamphetamine to another person.
By way of explanation, the 42-year-old told police she let people smoke drugs at the address "as it keeps them off the street". She also denied offering or supplying drugs and, incredibly, blamed the 13-year-old as being responsible. At her son's trial at the High Court, she was supposed to give evidence about his life on his behalf. She never turned up.
She has since pleaded guilty to offering to supply a Class A drug and was sentenced to 300 hours' community work and intensive supervision when she appeared in the Auckland District Court this month.
According to Radio New Zealand, the mother wiped away tears as Judge Evangelos Thomas spoke of how her "appalling" background had flowed on to those in her care, including her son and those who suffered at his hands.
Drug addiction had fuelled her behaviour but Judge Thomas said the focus of sentencing was the methamphetamine charge - not any of her other mistakes.
"You will live with those for the rest of your days, as will plenty of others to their great sadness - and, to no doubt, yours."
Mr Tamihere said the wider family was well-known to social agencies in West Auckland.
"The problem with this kid is he's born into a family that is already a vortex. His grandparents were in gangs and marginally employed, at best. So [his] parents were born into dysfunction, which they'd say is normal," said Mr Tamihere.
"Piss and dope is on the table, everyone is going to have a good time, therefore it's a good thing. 'We're eating well today, we've done a burglary', therefore stealing other people's stuff is a good thing. When you're into the third generation of that, you're in a very tough spiral.
"Unless interventions have occurred earlier in life, when they first come to the attention of officialdom, those ingrained behaviours - even without a brain injury - are tough to break."
His solution? "There are 350 families in West Auckland that I'd ringfence. I'd take the kids out, pretty quickly, and micro-manage the so-called adults in the family," said Mr Tamihere.
And removing the child most at risk is not just for their benefit.
"The likes of [him] in this world, they are kids that can disaffect and lead. They create knock-on impacts on siblings, cousins, nieces and nephews in the house, other kids at school ... so there can be a high cost of fixing that one bad apple."
Information-sharing and data matching between government agencies was also crucial. "There's police intelligence, Winz data, Housing New Zealand data, CYF, schools, Waipareira in and out of their lives ... but you know what? There's no one standing over everyone who says 'no no, you're not pulling your weight, you can do more'," said Mr Tamihere.
"Nothing's going to change because the systems that we've got won't talk and act together. There will be another case around the corner."
Dr Russell Wills, the Children's Commissioner, listened intently as the Weekend Herald recited the teen's childhood. "The first thing I would say, is the family have failed this child. And it's not at all surprising that a boy born and raised into a household with drugs and domestic violence would have this ending. It's tragic, but not at all surprising."
These are the families that "the system" has the worst success rate with, said Dr Wills. "There won't be any one culpable agency: everybody let this boy down. This is the repeated story in every death review I've ever seen dating back to James Whakaruru," he said, referring to the 4-year-old murdered by his mother's partner in 1999.
"All those reviews find the same thing. No one takes responsibility. Information is not shared. When families fail to engage, they aren't followed up. This is not surprising. In fact, it's heartbreakingly typical."
There was no silver bullet, as the repeated problem showed how difficult it was to change, but Dr Wills said sharing information about the child and their parents was at the heart of the solution. "The reviews find that the everybody has a piece of the information but we don't sit down and share. No one puts the whole story together."