You have this 'moral' standard that says 'it's wrong to kill someone' - and then... someone who commits murder... as punishment they are condemned to death? That doesn't make sense to me. If killing someone is wrong, then it's wrong whoever does it. To say otherwise is making like certain people have more of a right than otherwise to judge who should live and who should die, and I think that's very suspect indeed, to put it mildly.