I'm not sure that tougher and tougher sentences are the whole answer (although they may be part of it). I think there are definitely big issues around male identity, the macho cultures in which boys and young men are brought up and the violence that some children unfortunately experience at home from a young age. I've seen boys who are actively encouraged to appear 'tough', to challenge and always hold their ground and to generally be aggressive, by parents who think that this is what being a man is about. It can breed a climate of fear for teenage boys who are terrified of losing face, of being seen as weak. I dunno, just my observations, i could be way off the mark. It is incredibly sad when this stuff happens though.