Genesis 9:5-6 says, 'Surely for your lifeblood I will demand a reckoning; from the hand of every beast I will require it, and from the hand of man. From the hand of every man's brother I will require the life of man.
6 Whoever sheds man's blood, by man his blood shall be shed; for in the image of God He made man.'
Romans 13:3-5 says, 'For rulers are not a terror to good works, but to evil. Do you want to be unafraid of the authority? Do what is good, and you will have praise from the same. For he is God's minister to you for good. But if you do evil, be afraid; for he does not bear the sword in vain; for he is God's minister, an avenger to execute wrath on him who practices evil.'
I believe that societies have the prerogative under God to administer the death penalty for premediated murder. The fact that our criminal justice sytem does not operate perfectly means that when their is any doubt, we should probably err on the side of life.