The judge who sentenced Far North paedophile James Parker says he stole the innocence of the boys he abused and has done incalculable harm to his community.
Parker, who was deputy principal at Pamapuria School, was sentenced to preventive detention, with a minimum of seven years in prison and lifelong parole, on Thursday.
Parker, 38, previously admitted 74 charges ranging from indecency to sexual violations of 20 boys from 1999 to 2012.
He will not be released from prison until he is deemed safe to be in the community.
During sentencing in the High Court in Whangarei, Justice Heath said when victim impact statements were read out he'd hoped Parker would gain insight into the harm he had done.
"You may or may not have got that greater insight. However, I could not help to notice that when you were listening to the statements you did not even have the courtesy to look the victims in the eye. You simply sat there holding your head in your hands and not looking towards them."
Justice Heath said Parker's actions had damaged the trust not only of his pupils and their families but potentially the trust all parents placed in teachers.
He said he was sentencing Parker to preventive detention because he was not satisfied the community could otherwise be protected, on his eventual release.
One of Parker's victims wept in court but looked directly at him as he read his impact statement, calling him a "sicko" and describing how he'd grown to hate his family because they believed Parker over him.
Crown prosecutor Mike Smith described the damage Parker had done as incalculable.
He said even preventive detention would not repair the damage that had been done.
Parker's lawyer asked for a finite sentence, saying it would give his client a better chance of earlier treatment for his sexual deviance.
Alex Witten-Hannah said his client accepted the shame and guilt was his alone. But he said Parker deserved some mercy.
He said Parker did not use brutality or force.
Security was tight at the court building on Thursday. Bags were checked through an X-ray machine as people arrived.
An audio visual link was set up to a second court room to accommodate the public and media.
Justice done - police
The police have praised the boys who blew Parker's cover.
The detective who led the investigation, Mark Dalzell, says the kudos for putting Parker behind bars should go not to the police but to the first boy who had the courage to speak up about Parker's abuse last year - and refused to back down.
"If it wasn't for him, then goodness knows where we would have been today; where this would have stopped."
Mr Dalzell, of Kaitaia's Child Protection Team, says it was extremely difficult to get many boys to talk about Parker's abuse and the first to do so displayed heroic courage.
Mr Dalzell says justice was done by Thursday's sentencing and the families are happy with the result.
But Mr Dalzell says he's disappointed he wasn't able to stop Parker sooner.
He says one of Parker's victims was first interviewed by the police in 2009 but later told them he was lying.
He says the police were unaware at the time that the boy had been pressured by Parker and his family to retract his complaint.
"We didn't have any evidence. That was what was missing in our long evidential video interview, conducted with a specialist interviewer, where the boy advises that what he said was actually a lie, doesn't constitute evidence."
Treatment to start soon - lawyer
Mr Witten-Hannah says his client has been given a compassionate sentence that will get him the help that he needs.
He says Parker's treatment in prison will begin almost immediately.
"I think that slowly society is coming to realise that the sooner we treat these people the better; that it's a nonsense to leave them in jail for years untreated and then expect when their release date is near that somehow you'll be able to fix them and release them on the street."
Mr Witten-Hannah says Parker is deeply remorseful for the harm he has caused.