What steps has Harry taken to investigate the characters of those killed by Voldemort? You'd think that he'd kill/order killed, in particular, people that he did not care to have around in his future realm, once he took power. I'm assuming that the Dark Mark comes with its own self-destruct switch, so he does not have make sure any Death Eater dies. People killed by Death Eaters in self defence do not count.

This might explain why, for example, he did not kill Dumbledore, or any of the truly awesome people in the OOTP (Moody, et al), because he knew that they would be reasonable subjects.