> a police officer in front of the classroom who was enabled to boot the dysfunctional future criminals from the classroom

Well, that sounds like a way to make more future criminals. Maybe send the police officer to the parents instead. If the goal is to systematize the production of healthy, non-broken adults, we want to get those children more of a healthy environment, and less of an unhealthy one—send those police officers to watch the parents, and boot them out if they're making their child dysfunctional. (Really, if we had as many social workers as we had teachers, a lot of things about lower-class life could be fixed.)