The children who tortured and murdered another child in Britain (look for Jamie Bulger, the British kid, not the Boston mafia boss) got a name change and identity protection. At least one has since done it again. But Airstrip One is too civilized not just to execute but even to lock evildoers up and throw away the key.
Casey Anthony went free. Probably because she was "too hawt" to be convicted by a jury despite all the evidence against her. And this was in a state which is maybe the toughest against us.