"How can we claim the moral authority to judge?"
.,,.
Depends whom you mean by 'we'. If you mean society as a whole, then that is what we elect representatives for: to enact laws embodying such procedures on our behalf which ipso facto makes them legal ~~ ie gives them 'moral authority'. That is the place for "institutional killing outside a war situation". I am not saying whether I think it right or wrong to enact so, becoz, as I said above, I can see virtues in both sides of the argument and remain uncommitted on it. But I am just seeking to answer some, what seem to me, rather ingenuous [or perhaps disingenuous] questions.

~M~