The Principal Youth Court Judge believes there is a "staggering and profoundly concerning link" between children who have been in care and crime.
Justice and education advocates have said their sectors need more collaboration with the state welfare arm, after a critical report on Child, Youth and Family (CYF) by the Children's Commissioner.
Principal Judge Andrew Becroft said the report was a vital piece of work.
He said the Youth Court dealt with the most damaged, dysfunctional and disordered young people in New Zealand, and the overwhelming majority of them had a care and protection background.
In his job, he comes across thoughtful young people, but from their perspective, the care and protection they have received has been atrocious.
"We know that, as night follows day, the inevitable path of those for whom care and protection is not done well is the Youth Court."
Judge Becroft said he was in a Youth Court recently where a boy was not obeying his bail.
"I said, 'why can't you, why can't you stay still in this place,' and he said, 'you know, I've been moved by the Government through CYFS over fifty times, fifty different homes, now you ask me to stay still'."
Judge Becroft said it sounded simplistic, but what the report highlighted was the need to do the care and protection work better.
"So that we're not left, for instance, with, as I understand it, 83 percent of prison inmates under 20 have a care and protection record with Child, Youth and Family.
"There's really a staggering and profoundly concerning link between care and protection issues and adverse life outcomes, shall we say, in the criminal justice system."
Susanne Jungersen is the principal of Porirua College.
In her job, she comes across young people without a stable environment to go home to, and some find the place they leave in the morning is not the one they go back to after school.
Ms Jungersen said the uncertainty often led them to not want to commit, and hindered their schooling.
"In a general sense, they also are quite street-smart and have a bit of a sour view about the adult world that can lead them to become angry at school sometimes or to find school a difficult routine to follow."
Ms Jungersen said the CYF service was incredibly stretched and it did not have the resources to work with.
She said things could be improved if schools had better relationships with their local CYF office, and it would make more sense for education and welfare worked more closely.
"I do wish we had a better relationship, it would be very sensible if we sat down and did an education and welfare care plan together, that would make a lot of sense, that doesn't happen for the most part."
Post-Primary Teachers Association (PPTA) president Angela Roberts said her organisation had long pushed for schools to act as hubs, so other agencies such as health or welfare, can easily connect with children.
She said children going through state care were often very transient, and often schools were not aware students were in care.
"It's quite possible that schools aren't even aware of the really vulnerable circumstances that they're carrying on their shoulders when they walk through the school gate.
"So being able to resource schools to have the time to be able to connect with the other professionals that are involved in the child's life would be really welcome."
'Government has to get it right'
The Government has said there may be changes for Child, Youth and Family, but not until an independent panel it has appointed reports its findings, which are expected at the end of the year.
The Prime Minister acknowledged there was a strong link between children who had been in state care and crime, and said the Government as a whole needed to do a better job.
John Key said Judge Becroft's points were fair.
"There are too many young people who are so badly damaged from the environment they come from, and we need to do a better job as the State, actually, to try and look after them.
"That's part of the reason that Child, Youth and Family has such a significant review being undertaken."
The Labour Party said the Government must get things right for children in state care or risk more young people going into a life of crime and filling up the country's prisons.
Labour's Corrections spokesperson Kelvin Davis said Judge Becroft's comments did not come as a surprise and there was a massive problem with the state care system.
"The first thing that needs to happen, of course, in the lives of kids is that they need to be raised in a loving, caring, environment. Now if parents aren't doing that and they go into CYF care, well then the CYFS people need to actually be loving, caring, and supportive as well. Too many of our kids are basically just dumped and left," Mr Davis said.
Mr Davis said lessons must be learnt from the Children's Commissioner's report.
New Zealand First social development spokesperson Darroch Ball said the link between state care and crime was an "absolute failure" of the Government.
"We can't keep accepting that that's the path for these children. When they end up in the court system that's the end result.
"We need to start looking at the causes for that and really investing and supporting and resouring those kids."