Seven years ago, a drunk driver ploughed into a car containing sisters Sania and Danielle King. Seven-year-old Sania was killed; Danielle, 9, survived.
It is hardly surprising that the girls' grieving parents, Neville and Veena King, have been protective of Danielle ever since.
So when she came home this year with injuries allegedly sustained at the hands of police, it cut deep.
The Hamilton family claim Danielle, now 16, was "thrown around like a rag doll" by officers trying to break up an out-of-control teenage party. She was pushed to the ground, they say, before being dragged face down and chucked into a paddy wagon.
"She had a nasty black eye, serious grazes on her face and suffered headaches for days," Neville says.
He doesn't excuse the behaviour of some of the teens, but is furious at the "excessive violence" levelled at his daughter who he believes was cooperating with officers.
"Police turned up with AOS-type gears on - not gunned up but masked up, and she bore the brunt," he says. "I am angry."
Police said they were happy with the way officers dealt with the situation and the Kings are awaiting the outcome of an Independent Police Complaints Authority investigation - but they fear the officers involved won't be held to account.
"The worst thing is police are using any possible excuse, other than that it was their own doing. I almost feel as though the police are untouchable."
Danielle King's case is one of a string of complaints against police that are raising questions over the ability of police to investigate their own.
The question about police investigating police finds its roots in 1970 in rural Pukekawa, South Waikato, when the bodies of Harvey and Jeanette Crewe were found in their living room.
Neighbouring farmer Arthur Allan Thomas was found guilty of the murders in 1971 and again at a retrial in 1973. But in 1979 he was granted a pardon on the basis that the case against him was not proved beyond reasonable doubt. The following year, a Royal Commission of Inquiry found police had planted a shellcase used to wrongly convict the farmer.
Until then, middle New Zealand had, for the most part, trusted the police.
The brutality of the 1981 Springbok Tour riots was the catalyst, though, for the Government to do something. A Labour government established the Police Complaints Authority in 1989. The authority was one person with a few support staff, reviewing evidence police supplied. It did not conduct its own inquiries until 2003, when it was allowed to hire investigators - former police officers
But because of its primary reliance on police investigations, the authority was always perceived as lacking independence so, in 2007, the Independent Police Conduct Authority (IPCA) was established.
Last year, it received 1874 complaints and investigated 87. The most common complaints were about practice and procedure (475), attitude or language (382); failure to investigate (222); and use of physical force (219).
Due to its small number of investigators, the body passes most investigations to police to investigate, under its oversight.
Authority chairman Judge Sir David Carruthers says he is "extremely pleased" with the quality of investigations here.
"I think there is a huge advantage for our investigators to be ex-policemen because they understand the business and sometimes knowing what it's like to be there can help you to investigate better.
"These are people who can't bear the thought of police letting themselves down. Sometimes police are harder on their own."
The authority can summon witnesses and gather evidence. It can recommend charges, but cannot lay them. Last year, it recommended 74 improvements to police conduct, policies, practices and procedures. Less than half - just 32 - were accepted by year's end. The rest were still under consideration.
Police Association boss Greg O'Connor says police officers are best-equipped to conduct a quality criminal investigation. "To be quite honest, if there is a wall of silence the people who know how to get behind it are former police officers," he says. "I think the quality of investigations would drop away considerably if you didn't have former officers."
Labour's justice spokesman Andrew Little, however, is more concerned. "The IPCA will deal with the very serious complaints, and high-profile ones, but a whole bunch of others end up getting investigated by serving police officers. I don't think that's right."
The authority's five investigators are all former police officers, from New Zealand and overseas, bound "by the old codes of solidarity", Little says. "There is an issue of how much they can be expected to confront and deal with former fellow officers even if they didn't serve alongside each other. Police will always want to maintain their reputation and I think it can be difficult to cross this threshold and say police got this seriously wrong."
When police Inspector Richard Wilkie discovered his daughter had snuck out and was hanging out at a local park, he lost his cool - as many dads would. But when the off-duty officer kicked and swore at two teenage boys, he crossed a line. Two junior police officers had the situation under control until Wilkie turned up. According to a subsequent summary of facts, they were disturbed by what they had witnessed and, knowing Wilkie to be a senior police officer, "reported the incident to the supervisor at the conclusion of their shift".
Wilkie was a Counties Manukau area commander, so detectives from the neighbouring Auckland district were called in to investigate. But it was not until after the Herald on Sunday revealed the assault, two week later, that charges were laid. Wilkie pleaded guilty to assaulting the two teenage boys.
High-ranking Whangarei police officer Mike Blowers was charged with drug-related offences this year, as were West Auckland cops Peter Pakau and Lotovale Perese.
Police Commissioner Peter Marshall says the recent prosecutions show police "will not hesitate" to thoroughly investigate staff facing allegations of a criminal nature, and will put them before the court
He says the police staff of nearly 12,000 are held to a high standard and points out the number of complaints about police are down.
But new lobby group Clean Up Our Police Service is concerned at the number of officers facing criminal charges and at the number of highly critical IPCA reports on police pursuits. It is also concerned over police shootings in Porirua, Waitara, and most recently on Auckland's Northern Motorway.
Spokesman Dick Cuthbert has written to the Government calling for the establishment of an English-style Criminal Cases Review Commission.
But Minister of Justice Judith Collins says such a commission would not extinguish debate about miscarriage of justice, pointing to the controversy over such high-profile cases as David Bain, Peter Ellis and David Dougherty, referred back to the courts under the Royal Prerogative of Mercy. "This is just what an independent body like the UK commissions would have done if it had looked at these cases," Collins says. "After a case has been referred back, it is then up to the courts to decide the outcome."
Cuthbert disagrees: "All these historic convictions highlight what is increasingly seen as faulty police investigations," he says. "Failure to resolve them has led to a decrease in confidence in the justice system and the police in particular."
It was late at night when Christchurch pensioner John Bennett heard what he thought was an intruder - so he ventured outside with an air pistol and a tee-ball bat to check. What the 66-year-old found was armed police looking for an offender on the run.
Bennett was made to lie face down in sewage and bitumen.
The retired city council engineer, recently fitted with a pacemaker, says the officer pushed his head into the ground, placed his foot on his shoulders and cuffed him. "I didn't have my glasses, I was in my underwear with barefeet," he says. "He was a nasty bugger."
Bennett says his wife, who had been battling cancer, was screaming out for the officer to stop. But Bennett was taken to the station and held until the morning "without even being offered a blanket or a glass of water".
An internal police investigation found the officer had acted with reasonable force. But last month, the Independent Police Complaints Authority found his arrest was "unjustifiable and unreasonable".
Bennett says: "Our trust in police has completely gone. The police should lay charges against their own because if somebody else did that they'd appear in court the next day."
District Commander Superintendent Gary Knowles said last month that an officer has already received "additional training as a result of performance issues" and the authority's findings raised a number of points that would be considered - but no further disciplinary would be taken.
Another city, another party, another injured girl.
"My daughter Ella is a slight 15-year-old girl," says Nikki Healey, of East Auckland.
"She was shoved in the back by a male police officer with such force that she crashed to the ground and knocked her two front teeth out clean from the root."
Ella Eketone claims she fell face first on to concrete after being pushed by police. The officer involved was cleared in an internal investigation, her mum says, finding police had used "reasonable force".
Ella faces continuing dental care until her mid-20s, when dental surgeons hope to be able to give her permanent false teeth.
"It is very difficult to understand how an internal police investigation found the actions of the police officer concerned, in those circumstances, to be acting with reasonable force," her mother says.
The family has laid a complaint with the Independent Police Complaints Authority, but their lawyer John Munro believes the Authority needs greater powers.
"An ideal situation would be for the IPCA to have more teeth," he says. "A purely independent body that has the authority to bring a prosecution."
IPCA chairman Sir David believes the model we have here is a good fit, working cooperatively with police.
"I think it's much better that we don't have those powers [to arrest and prosecute] because it give us an openness and access to police officers that otherwise you don't get," he explains.
"And I've seen how closed they can be in other countries when they've got the power to prosecute.
"For us, the big weapon is publicity and public attention ... police are really anxious to make sure they do the work well and are respected for it," says Sir David.
"We do have investigations where we think police haven't got it right and come out with a different conclusion - but I struggle to find an example of where we've done that and the police haven't eventually said, 'yeah you're right, and taken on the recommendations'."
In Hamilton, Neville King certainly hopes the authority can deliver a fair recommendation.
He fears his 16-year-old daughter, though, has lost faith in the police.
"At the end of the day the police always have the last say in everything. They were responsible for her coming home in that state," he says.
"What's to stop it happening again in the future? If an officer had the same injuries somebody would be charged."
Independent review can protect innocent
Sam Hallam, one of Britain's youngest victims of a miscarriage of justice, served seven years' jail for a murder he always denied.
He was 17 when charged with the murder of trainee chef Essayas Kassahun, who died after being attacked by a group of youths in London in 2004.
Hallam always maintained he was elsewhere on the night of the killing and pleaded not guilty. His first appeal was dismissed in 2007. The following year the Criminal Cases Review Commission launched a thorough investigation.
It found a range of issues, including new evidence, raising the possibility that his conviction could be quashed, and referred his case back to the Court of Appeal.
The prosecution had failed to investigate Hallam's alibi, including crucial CCTV footage and mobile phone data showing he was somewhere else when the murder was committed.
On May 16 last year, the Court of Appeal freed Hallam on bail and the following day quashed his conviction.
London barrister Dr Malcolm Birdling, a New Zealander, says the British experience demonstrates the importance and urgency of establishing a Criminal Cases Review Commission in New Zealand.
Birdling's doctoral thesis compared the New Zealand Royal Prerogative of Mercy System with England's Criminal Cases Review Commission.
"A criminal justice system must recognise this unavoidable scope for error, and have procedures to identify and fix errors when they occur," he says. "Only then can the public have confidence that the system is convicting the guilty, and acquitting the innocent."
Birdling says any further delay risks a crisis of public confidence in the criminal justice system.
"An independent Commission would also mean the decision as to whether or not to refer a case for further consideration by the Court of Appeal would be made by an impartial body, and not (as at present) by civil servants at the Ministry of Justice, and ultimately the Minister of Justice."
Decisions about guilt or innocence, he says, should be made following a transparent process, "and not by civil servants or politicians behind closed doors.
Birdling believes high-profile cases like David Bain and Arthur Allan Thomas are just the tip of the iceberg.
"What worries me is the cases we don't know about, and without an independent Criminal Cases Review Commission we may never know about."