The nurses, doctors and social workers who work at the frontline of child abuse are victims too. They see the bruises and breaks, hear the heart-wrenching stories, work the ventilators that keep beaten, broken, children alive - and take the anger.
At the Starship's Paediatric Intensive Care Unit (Picu), nurses are routinely harangued by families who will not accept their child has been abused - even if they did it themselves.
"One of the things that makes child abuse worse is the active hostility towards you," says Dr Patrick Kelly, leader of Auckland City's Child Protection Team, Te Ruruhau.
"The person responsible never discloses completely what they did. Much stress in the hospital is due to denial, people saying, 'How dare you accuse someone in our family!' We are not working with these families but against them. And there's often a big cultural divide.
"The key that holds us together is the team meeting we have every morning and for a half day each week," says Kelly. "It gives us the ability to discuss these cases, mouth off, express anger. It's a very important part of dealing with it."
Kelly, whose team deals with around 600 new cases of child abuse every year with Child Youth and Family social workers and the police, also keeps his sanity by going home to his own four children aged between 6 and 12 "where life's so busy I can't really think about what's been going on at work".
Unlike the system in CYFS, where workers sit with their supervisors, there is no formal direct supervision, even for junior nurses. "That hasn't been a traditional part of medical and nursing practice," says Kelly. "You basically get on with it."
One Picu nurse says that abuse cases are much more devastating than nursing ordinary sick children.
"You're dealing with the whole family dynamics, with the cops, the parents - you know you're not just dealing with the kid in the bed. And when you run into three or four cases over a six-week period it really burns you out," she says.
"It's not sexual abuse, predominantly physical abuse - just kids getting bashed around. It's terrible. I never knew it was so bad till I went and worked there."
The more she talks about it the more desolate she sounds. "It does make you wonder what sort of society we live in that we can beat up our kids as much as we do."
Nurse Christine Prentice found working at Starship's intensive care unit upsetting as she had a young son of her own. She came to the Starship from the Greenlane cardiac unit where she enjoyed crisis nursing, but this was a different kind of stress.
"It was very traumatic dealing with the non-accident injuries," she says. "You've got them from infants up - little toddlers who've supposedly 'fallen over or fallen downstairs' - which isn't true. I decided it was making me quite upset."
Much of the time, nurses in Picu work one-on-one with the sickest children, stabilising their breathing, heart rates and injuries. "It's intensive nursing," she says, "particularly when you're doing 12-hour shifts."
Despite the support of her colleagues she moved to North Shore Hospital, where she now works in the special baby unit.
These professionals say some of the most harrowing cases come from children who have just learned to talk as they describe in court what amounts to torture as though it was part of normal life - which for them it is.
Paediatrician, Teula Percival, who runs Middlemore's Child Abuse Clinic says, "it's really distressing because you hear everything. They've been beaten with broom handles and vacuum cleaner pipes, locked in things, kept home from school because they're so bruised their parents are scared they'll be found out. These poor kids have been really, really, beaten and that's just the norm for them."
Then there are the babies who can't speak. "It's very distressing. They are little babies and you can see someone has beaten the hell out of them." She says the most frustrating thing is that "we get all the different stories, people change those stories".
All of which means much of Percival's time is frittered away, trying to sort abuse cases through the courts and remove battered children from danger. But, as in the Kahui case, so often it doesn't happen. "You can't specifically pin the assault on one person. A lot of these children don't get justice in our system - no one even gets charged."
"And it keeps happening," she sighs. "I have a half-day clinic every week and it's filled with abused children, four or five in that clinic, two or three coming through the Emergency Department. The same number this year, and last year, and the year before that."
How does this woman, who has given her life to caring for small children and who has three of her own at home, deal with it? "You have to step back because it becomes overwhelming. We unload on each other."
For the police, "it's just business as usual," says Detective Sergeant Philip Kirkham, leader of Auckland City's 10-strong Child Abuse Unit.
"We deal with it day-in and day-out, so you build some immunity, distance yourself emotionally. If you personalised it you couldn't do your job."
Kirkham says officers with young children are often most affected by child abuse cases, and that the police have systems to look after them. "It's not like the team works on things as individuals."
Those who suffer psychological trauma are offered counselling and psychological support. "They can go and see a psychologist every now and again to make sure they're psychologically fit and healthy."
Psychologist Kerry Gould, says the best way to cope with on-the-job trauma is to rely on professional training, backed by regular, frequent, appropriate, supervision. "That way, you can debrief and get your sense of equanimity restored, restore your faith in humankind."
She suggests forcing yourself to remember that abuse isn't the norm. "Most children are treated lovingly and carefully."
Being a professional gives nurses and doctors something to do in times of crisis when we all feel called to action. "That's where the general public is at a bit of a loss at times like this.
"At the moment the call to action is to be a busy-body. It needs to be followed by a call to action to be nice to children - all children."
Kelly's call to action is to galvanise the health service. "We could be doing a whole lot better," he says.
His ideas sound familiar, sensible and workable: "Universal screening of some sort, a targeted, intensive home-visiting programme, plus a good, robust network behind the primary care workforce.
"It's time the health service stepped up to the plate and took a public health approach like we do for diabetes, smoking, and the rest."