This story contains descriptions of violence some people may find distressing. Two people who mistreated a toddler until he died escaped murder charges because prosecutors have an incentive to "dispose" of cases quickly, claims the Sensible Sentencing Trust.
David Haerewa, 43, and Tania Shailer, 26, instead pleaded guilty to manslaughter. They had agreed to look after three-year-old Moko while his mother was with her oldest child in hospital.
Haerewa admitted assaulting the toddler over the course of two months, including kicking and stomping on him, rubbing faeces in his face and keeping him locked in the bathroom for hours on end.
Moko died on August 10, 2015, after being found covered in bite marks, with swelling so bad he couldn't open his eyes and a ruptured bowel.
"It was premeditated, it was prolonged, it fits the criteria of murder," says Sensible Sentencing Trust founder Garth McVicar.
"It was really the legislation that encouraged the Crown prosecutor to do a plea bargain. That is the problem here."
He points to changes made in 2013, which saw prosecutors move to bulk-funding. At the time, Solicitor-General Mike Heron said bulk funding "provides incentives to be more efficient". The change also saw the overall level of funding for prosecutions cut by 25 percent over the course of a few years.
Mr McVicar says his organisation still gets complaints about the change "on a daily basis".
"The quicker they can dispose of a case… the higher the hourly rate for the prosecutor," says Mr McVicar.
"Ultimately they got rid of it -- it's manslaughter, got a guilty plea, got rid of it quicker and the prosecutor's got an increase in pay."
Anthea Simcock, CEO of Child Matters, says more people need to be aware of the services available to help children in need. There is a number, 0508 FAMILY, which few people seem to know about.
"What we need to do is make sure everybody has that information, just like 111 -- people can ring that if they really need to, but it's 0508 FAMILY that they can call. We need to get that information out there," she told Paul Henry.
Moko's torture was witnessed by other children living in the house. Ms Simcock says they need to be looked after so they don't become tomorrow's child abuse perpetrators.
"It's a lack of empathy, it's a whole different mindset. People are not born that way, but they can be rewired through their own violent experiences and through other methods -- drug-taking and alcohol," she says.
"We really need to put services around those children… that they can learn to live safely in a trusting environment. It can happen, but it's going to be intensive."
Child, Youth and Family is undergoing a major reform, expected to be in place by March 2017.