Police Armed Response Teams (ARTs) are being criticised for attending callouts to deal with children as young as 12 while they were in action.
The controversial teams were officially scrapped this week, but data shows the armed units were called out to several incidents involving children during the six-month trial.
Armed officers dealt with six incidents involving a total of eight 12-year-olds - seven of whom were Māori. The other 12-year-old's ethnicity was reported "unknown".
Almost all of the incidents took place in Hamilton, where Lady Tureiti Moxon runs Te Kōhao Health.
"When there's already a tarnished relationship, or lack of trust between Māori as a community and policing, what is that entrenching in those young people and their whakaaro and relationship with police - it should never happen."
Judge Becroft said it would only be in extreme circumstances that armed police should deal with children.
He's disappointed - and said what's happened could have a lasting effect on those young Māori.
"I want early interactions for children with police to be positive, constructive, and build trust and confidence.
"Not confrontational, traumatic events that can influence attitudes for life."
Fears ARTs will target Māori realised
The Armed Response Teams trial was widely criticised - with many concerned that they would target Māori.
In the end, more than 50 per cent of the arrests and uses of force by ARTs members were against Māori.
South Island Whānau Ora leader Helen Leahy said she was sad to hear Māori children were targeted.
"The thing that worries me the most is that this is about institutional racism," she said.
"This is about the fact that force is being used disproportionately against Māori and the Pacific communities.
"When it comes to our Māori children, where is the role of the police to create good relationships and cultural safety?"
A Mānukau barrister specialising in youth offenders, Kingi Snelgar, said the latest findings confirmed his suspicions - that the teams would disproportionately harm Māori.
The situation should have been handled differently, he said.
"It should be an absolute last stop, there are so many things police can do before turning to firearms, and especially when you have children, [or a] vulnerable child," he said.
"Often Māori children will have negative relationships with police already so using guns to lock up or to apprehend children is just totally unnecessary and a complete misuse of that power.
"I can't think of, in my mind, any justification for using arms against young Māori and what that does is just continue that legacy of police using power against Māori which has been happening for generations."
Police announced this week the Armed Response Teams would be scrapped for good.
Snelgar said he was glad they will not be rolled out across the country, but the problems were not over.
"There are deeper institutional issues within the police that need to be deconstructed if we are to move to a society where people are treated equally and not judged because of their race.
"There is global recognition now of the dangers and the misuse of police power."
Police declined to be interviewed but in a statement said during the trial, which ended in April, the teams were deployed to a range of policing jobs.
"Many of which were responded to as general duty callouts, and did not require the presentation of a firearm," police said.
"It's important to note that in some of these instances young offenders were carrying weapons such as knives, and that there were often other, older offenders present also."
Police said no use of force was employed against a 12-year-old during the trial.
They said they did not always have full information about an alleged offender before attending an event and were committed to treating people fairly, and improving outcomes for Māori.