Bill welcomed by the Bill
"The chance of children growing out of offending gets smaller with each offence," he says. "By the time they get to court, they've done their GCSEs and A-levels in crime. Appearing in court is their master's degree and jail is the PhD."
One 17-year-old he'd seen recently had had 36 supervision orders. "It'll be a hell of a job to get him back on the straight and narrow," says Mr Butler, who is also the Association of Chief Police Officers' spokesman on youth issues. He knows that low attainment and the resulting loss of self-esteem are key factors associated with juvenile offending. So he remains sceptical about the Government's back-to-basics drive in primary schools.
"I don't have any problem with excellence," he says. "But the reality of the world is that children aren't all excellent at maths and reading. Some excel at music or sport, and those give children the opportunity to participate in a group, to be good at something, to have some kind of recognition in the school. Narrowing down the curriculum is in effect disadvantaging some children. "
Mr Butler is aware that teachers face a growing problem with disruptive pupils, trying to cope with bigger classes at a time of unprecedented public scrutiny. They can't be blamed for wanting to exclude violent pupils, he says. But he urges them to "have a thought" about what happens to the children they exclude: "I'm not running a round-up service for young people kicking around in the streets."
He urges a joint approach to the problem by schools, the police and social services.
He has reservations about the Government's plan to introduce local curfews for under-10s and says they should be used "very sparingly", adding: "It's not in the public interest if their use alienates the majority of young people in a community."
The Government's proposals provide a "great opportunity" to collaborate on preventing juvenile crime, Mr Butler says. He stresses, however, that the plans will need resources and changes in the way police performance is assessed. As he says: "I'm not being measured on the number of drugs talks I do in schools; I'm being measured on the number of burglars I catch."