You mentioned earlier that we (in the USA) have a legal system, and you're right.
Until we have a true justice system I think that the more people who feel compelled to get involved in issues they find troubling the better. Maybe this jerk of a kid gets his case dismissed via our legal system due to some legal technicality...is he really innocent?
According to the law he would be. Unfortunately the law, which is there ostensibly to protect the people and thus society, only serves itself and is blind to right or wrong.
It's blind to justice.
And if that kid doesn't receive the punishment that society demands, the videotape he made to celebrate his monstrous behavior to another living creature still shows that he's guilty. And he always will be, in everyway that really matters. Which is why I'm not too concerned about what happens or doesn't happen to him legally.
Because knowing what I know now, if his resume ever crossed my desk he would not get a job. If he started dating my daughter it would end immediately. If he was broke down on the side of the road I'd drive by and not so much as wave at him. Whereas not everyone will feel that way, many will. Basically, his actions will ostracize him from many opportunities that he may otherwise have found available to him.
If there's a hell, maybe his will be filled with cats...