The Death Penalty: Whom Shalt Thou Not Kill?

Let’s examine one of the primary comandments of all major religions: “Thou shalt not kill.”
First, we must assume that this applies to killing other human beings…not cutting down trees, planting and reaping grain, killing animals for meat, or stepping on disease-carrying cockroaches. This is the dominant view of Westerners.
As for the GOP, I beleive we are curently in a quandry of contradictory stances. Is it okay to kill a convicted murderer, but not okay to kill a fetus? Is only innocent life sacred? If so, is Brittany Spears is asking for it when she sings, “I’m not THAT innocent!”? Of course, there are varying degrees of innocence. Where do we draw the line?
Is it alright for the government to execute criminals from an objective standpoint? If so, we must question the difference between one individual killing another out of vengeance or greed vs. a third party pulling a lever or pushing a button.
I am mystified by this quandry, and have considered it for years. On one hand, I beleive it is wrong to kill. But if a loved one were murdered by a criminal, I would want that person dead quicker than you can say, “Die, bastard!” By the same token, I also beleive that abortion is justified in certain circumstances.
Consider the idea that “Caeser shall do what is unto Caesar, and God shall do what is unto God.” It is a fairly convincing argument against the death penalty. My interpretation is that we may imprison, but not kill. In fact, in my mind, life in prison – especially for men – is a harsher punishment than death.
I beleive the GOP needs to address this issue, rather than simply taking a “pro-death penalty” stance. We need a more detailed and public account of what that atually enatails and to whom it refers.
I invite you learned folks to opine!