Principal Youth Court Judge Andrew Becroft said while it was not the job of a judge to commentate on political party policies, Mr Key's speech is a measured and thoughtful approach and is comparable to what is being introduced in the Western world.
"In England the parenting ordersand intensive surveillance policies, when done well, have proved pretty successful and there's no reason that they wouldn't be successful here," Judge Becroft said.
He said many involved in youth justice have advocated for parents to be assisted and held accountable for the actions of their children.
"We need to do much better in supervising and monitoring the sentences that the Youth Court delivers," Judge Becroft said.
But he said the Youth Court is misunderstood by the public and the media.
"Because young people start in the Youth Court, it doesn't mean they end in the Youth Court. There are a significant range of serious offences for which young offenders that begin in the Youth Court can be transferred to the adult district court for sentence," Judge Becroft said.
He said the Youth Court is sometimes thought of as a "slap on the wrist with a wet bus ticket, Kumbaya singing" soft approach court and but 60 young people are sent to prison each year.
"There is a legitimate debate at the moment about what kinds of offences can be sent to the adult courts but include, at the moment, aggravated robbery, aggravated burglary, serious assaults, serious sexual offences and the serious arsons," Judge Becroft said.
He said that while the emphasis is on turning lives around, there is still provision to deal with serious offenders.
But youth offending needs to be seen in the wider context and not in isolation of the rest of the population.
"Apprehensions for youth offenders as a whole is declining but a small group of 750 to 1000 young boys are offending more violently," Judge Becroft said.
He said the largest increase in violent offending has come in the 51-99 age group.
