I can highly recommend the Swedish documentary film They Call Us Misfits from 1968 and especially its successor A Respectable Life from 1979. They are both well-known and there should be English subtitles available.

The first film follows a group of wild youths who hang around in inner-city Stockholm. They were called "mods" in Swedish and lived a sort of hippie/proto-punk anarchist lifestyle. Remember, this was 1968, so this kind of behavior was completely unseen before in Sweden. They drank alcohol in public, generally didn't give a fuck, smoked pot and were noisy and arrogant.

The film maker grew close with a couple of guys in the gang, Kenta and Stoffe. They start out pretty harmless, with petty theft, hash and partying, maybe 16 or 17 years old. In the second film, oh man, you can't believe it's the same guys. The party fucking ended, to say the least. Just watch both of these films, it's my all-time favorite documentary films.

There is a third part, where they see what happen to the kids of these "mods" guys, but it's not as important in my opinion.