Option D) used to be really popular. Exile. The problem is there is no unclaimed land to drop them on anymore that makes sense.

Because really, the kind of extravagant violence to justify a death penalty is the kind that makes you want to do several things:

1. Not pay for their livelihood for the rest of their life. US prisoners cost somewhere in the ballpark of $150k a year to house, feed, etc. What a colossal waste of resources. 2. Not kill them, because thats barbaric and primitive. We are better than that. It even costs more to execute people than it does to imprison them forever, since the appeals and actual execution will run to the tune of millions.

So kicking them out of the club we call society seems like a the best option in my view.

The problem is, one, having somewhere to put them (I'm sure Australia would not be as much of a fan of having serial murderers dumped on their shores as they were two centuries ago) and two, keeping them out. But really, it seems to be like the moral / ethical maxima. If you break the most fundamental rules of society, to such a degree you are unfit to ever participate again, you are kicked out.