Kind of a dark thought, to think that we react differently to essentially the same crime based on whether we feel a need for not justice, but revenge.
That is not quite what he meant. The comic said that retribution does not apply in this case. So what most of us think of as justice does not apply in this case. The three purposes of punishment that do apply, rehabilitation, deterrence, and removal, have less to do with conventional notions of justice and more to do with utilitarian concerns such as maintaining public safety and in pursuance of that making law-enforcement and crime-prevention measures effective.
So then would the difference between an attempted crime and a completed crime be an issue of the depravity of the acts? Because if you try to kill someone, but fail, its not as horrific as if you succeed?
I’m not sure “depravity” is the right word. If you swung an axe at someone and missed, were you any less depraved than if you’d connected?
I’d suggest that the lesser punishment for attempt isn’t because you yourself were any less bad, or because what you did was any less bad, but because the consequences of that act were less bad.
Isn’t this a matter of deterrence as well though? If you know that trying to kill someone gets punished but succeeding gets punished worse, you might still feel you have a reason to back out before the end. On the other hand, if once you’re started on the attempt, the punishment is the same regardless, you’d feel you’re in too deep to back out now. Thus by having the punishment escalate the further in you get, we create an incentive to stop while you still can.