Well, he's not in jail, is he?
And would him being in there instead of out here make him any more repentant than he is today? Probably not. In there, he'd be surrounded by violence and rage and the sort of bullshit masculine pride that led him to bash this kid in the first place. But on the outside, he was able to get to know some gay people, get to explore the real world, have a son, and come to terms with how horrible a thing he did as a teenager.
Seeing this guy behind bars might make you feel better, and it might check a box on some karmic checklist of justice or vengeance or whatever, but incarceration does not in itself lead to redemption. That's assuming, of course, that you want guys like him to redeem themselves. If all you want is to see them rot in jail, that's a different story altogether.