In looking at the above quote, and viscerally recognizing the evil mind that spawned it, there is no place on earth that such an animal deserves to live.
I am all for law and order and justice and process. But a society that allows such people to claim one more breath of life is an unjust society, in my view. I would kill such a person myself with joy, if not for the consequences, and I would be absolutely secure in my righteousness for doing so.