Experts continue to put the slipper into the Government's so-called "boot camp" bill, with the top Youth Court judge saying military-style camps don't work and asking whether changes are really needed.

The Youth Courts Jurisdiction and Orders Amendment Bill seeks to provide the court with new sentencing options ranging from tight supervision to a three-month stretch in a military-style camp. It would also extend the court's jurisdiction to include 12- and 13-year olds who committed serious crimes and allow the court to issue parenting orders.

Principal Youth Court Judge Andrew Becroft told yesterday's social services select committee the bill proposed the most fundamental and deep seated change to the youth justice system since its inception in 1989. He queried whether the system's inadequacies were the result of something philosophically wrong or that it was overly complicated and poorly resourced.

The law surrounding 12- and 13-year olds was convoluted and difficult to understand and there was very little public scrutiny, he said. Therapeutic foster care was already available but there were not enough resources for the 60 to 80 12-to 13-year olds who would qualify for Youth Court.

"If the bill becomes law there is a real concern from Youth Court judges that the court will assume responsibility for the worst youth offenders.

"Yet the Youth Court will not have the necessary statutory ammunition to deal with the inevitable care and protection issue at the root of the offending."

Judge Becroft also said that if the term "boot camp" meant a short, sharp shock for a young offender, "we overwhelmingly know it doesn't work".

The offenders were better fed, healthier, stronger and faster but they were still offenders. Putting together young people with disorder problems and cannabis dependency meant their treatment and rehabilitation took twice as long as sustained intervention in the community.

National MP Chester Borrows argued that the words "boot camp" did not appear in the actual legislation.

But another submitter, children's lawyer Robert Ludbrook, knocked that back.

"This confusion about boot camp is entirely the responsibility of Government. [Boot camp] appears in the introduction of the bill and it appears in the press releases before and after the election."

He said young people responded better to programmes that educated them and developed their skills. There was no evidence boot camps worked on young people.