Child and youth offending statistics have continued their downward trend of the past few years, though youth violence continues to rise, particularly serious assaults.

The Ministry of Justice yesterday released statistics for police apprehensions for child offending (10- to 13-year-olds) and youth offending (14- to 16-year-olds) for 2008.

An apprehension is recorded when police deal with a matter regarding an alleged offence.

Since peaking in 1996, per capita youth apprehensions have fallen 18 per cent, and child apprehensions by 38 per cent. Significant falls occurred in theft and burglary.

Youth apprehension rates increased slightly in 2008, but have been mostly stable for the three years to 2008.

Serious assaults fell slightly for the first time since 2000, but remain high compared with the past decade and have risen 44 per cent since 1998.

Violent youth offending increased slightly to 198 apprehensions per 10,000 youths. While it increased 21 per cent from 1998 to 2008, it has risen only 2.5 per cent from 2006 to 2008.

In 2008, per capita apprehensions for violence was higher among 17- to 30-year-olds than youths.

Principal Youth Court Judge Andrew Becroft said the statistics punched a hole in the popular perception that youth offending was "spiralling out of control".

He said the cause of the steady increase in youth violence was difficult to pinpoint.

"Some of it is long-term factors, including abuse within the family, transience, early development of conduct disorder. Short-term risk factors ... If you took alcohol out of the violent offending equation, you would probably reduce the numbers in the Youth Court by 90 per cent."

He said fixing the system around child offending in the Family Court would have a significant impact on reducing violent offending.

"There would be every reason to think that there'd be a very obvious flow-through in reduced violent offending in the Youth Court, because risk factors would have been identified earlier.

"That's the age - 10 to 13 - when alcohol and cannabis abuse begins, that's the age when disengagement from school really begins."

Earlier Judge Becroft and Judge Tony Walsh, who sits in the family, youth and district courts, told Parliament's social services committee that the law around child offending was a mess.

"The system itself is deeply flawed, overly complex, convoluted and hard to understand," said Judge Becroft.

"I think it's fair to say that we might have dropped the ball, collectively, regarding our response to child offenders."

The law that governs the Family Court splits the welfare "care and protection" model from the criminal "youth justice" model, meaning they are treated as separate components.

Judge Walsh advocated inserting a separate part of the law for child offenders that would straddle the two models, and decrease the to-ing and fro-ing.

"The reality is that a young person, from a background of care and protection issues that range back over a long period of time, it is almost wishful thinking to think that in the Youth Court we can deal with those issues.

"Nine times out of 10 whatever youth justice issues there are, there will be care and protection issues as well," he said.

* Police youth apprehensions per 10,000, 1998 to 2008
* Aggravated robbery, 50 per cent rise.
* Grievous/serious assault, 44 per cent rise.
* Theft, 19 per cent drop.
* Property offences, 16 per cent drop.
* Violent offences, 21 per cent rise.
* Total apprehensions, 15 per cent drop.