In yesterday’s Herald Tribune Mark Essig wrote an interesting article about the death penalty: “It is the inverse of the guillotine. Rather than painless for the convict but gruesome for witnesses, the three-drug cocktail may be easy on witnesses but brutal for the victim - an inert body suffering unspeakable pain.
The Supreme Court may end up banning the cocktail, but such a ruling would only inspire state officials to mix up a new set of drugs. The new protocol may at first appear to work smoothly, but decades of executions have taught us this: Technical systems are prone to failure, and human bodies are irreducibly complex and idiosyncratic. Whatever the technique, executions will go horrifyingly wrong.
Pain is often a necessary part of death.”

Mr. Essig of course is right. We don't want the witnesses and executioners to watch how the convict dies a gruesome death.
Mr. Himmler came up with the idea of gas chambers to spare the German troops.