Same old story. I think that the fact that many of these youths are not on a career track gives them no fear of a massive future loss of income or social standing of being a party to arson or breaking into and demolishing the store.
I think there's also an issue of there being a segment of the population that sees jail as a normal part of life arbitrarily handed out by the system rather than punishment for their wrongdoing. The thing is the odds of being caught for any given minor crime are low--they're in a situation where the outcome of committing a crime are normally desirable (after all, why else would they commit the crime) and rarely bad. A low probability of punishment doesn't teach the right lesson and if anything is a recipe for mental illness.
I don't know how to fix the problem, though.