Hmm, Interesting question. I think the death penalty would be very difficult to operate efficiently and correctly at the same time. For example, after someone who was apparently proven beyond a doubt of being guilty is executed, new evidence surfaces proving they were innocent. But if it is 100% percent certain, I don't think it would be useful either. You cannot undo what has already been committed, killing them does not reverse the damage, rather the only situation I would suggest it would be if there was absolutely no other way of stopping them from committing a crime, like it's the joker and you know he's just going to break out and kill a bunch of people by next week (or something).
1. If it was just between me and some stranger, and there wasn't any foreseeable future consequences from that decision, I think I'd let him kill me before I killed him, but you never know, self preservation might have something else to say at that moment.
2. As I rambled on before, death doesn't bring satisfaction, or redemption, I think it should only be used as a lesser evil to the consequences of letting such a person go.
This is why morals and logic become rather interchangeable. If I think about this is the logical way of "preserve as much human life as possible", it brings me to thinking "is the preservation of human life really the moral high ground?", if we preserve and nurture to the point we're all living in squalor and poverty, and destroying the planet, was it really the right thing to do?
Oh, and Australia.