Report criticizes Iraq's executions; official defends justice policy - CNN.com
Two wrong don't make a right, and murdering someone is wrong, so, to 'murder them back' is wrong. This appeals to our survivla instinct as in fight of flight from a problem, and choosing to kill as in fight is wrong, to subdue is right. These people pose no further problem, as they are detained. If it is a human right to life then it is right to not intefere with thier rights. What does killing them achieve? It simply snuffs out more life. If they were killed then that would be the easy way out, to detain them is the right thing to do, as then you stop more harm from coming to the world, and harming them is more harm.
I suggest that interrogation be scrapped. Instead they can publicly hypnotise them, then wave their hands in front of their eyes to see if they blink, or something, then they will learn the truth. The defendants lawyers should be present to make sure they are treated fairly, and it will negate the need for interrogation, which isn't as effective anyway.
As far as the death penalty goes, it is primitive and appealing to the masses because they feel it is right based on their primal urges. When you get hit your instinct often says to hit back, but looking forward to reason leads to more secure measures.
Didn't a great man once say "An eye for an eye leaves the whole world blind"? Well in this case they would certainly stop them from doing more harm, but it is primal and not truthful.