Pop psych states that murder, especially first-time murder, induces lifelong psychological trauma in neurotypical adult people - and that, therefore, most of them lose more (I'm not saying "more utility") than they gain.
Clearly, that wouldn't be the case with the death camp survivor [1], but I can see a sane, relatively untraumatized civillian who'd volunteer for Hitler's post-war execution regretting their loss of innocence afterwards.
[1] I've heard that this was what happened with the commandant of Dachau and some of the SS guards there, who were turned over to the liberated prisoners by American soldiers, and presumably torn apart by them.
http://en.wikipedia.org/wiki/Dachau_massacre
Not being a murderer, regardless of the utilitarian pay-offs is an important part of people's identify and reasoning about morality.
It is fascinating just how damn crushing such tags can get once you start multiplying them. Even in the eyes of other people. Consider someone who has killed for the greater good. Now consider someone who has killed, raped and pillaged for the greater good (by historical standards this is the regular war hero pack).
Now consider someone who has killed, raped, blackmailed and tortured for the greater good. One may be glad tha...
If it's worth saying, but not worth its own post, even in Discussion, it goes here.