No, it may be a little more subtle than that.
I have no question, and history bears this out, that the great majority of lifers are not going to attempt, let alone succeed in murdering another inmate or a guard. And this has been true across the board - states with and without the death penalty.
There are, however, a small group within lifers who are high risk to murder again while doing life. Will the death penalty “deter” them from doing so? Perhaps it may with part of the at risk subset of lifers.
As noted, in the Washington case, this was at least his second murder, and it was in what is at least allegedly a controlled situation. In this particular case (because until his second murder conviction and sentence to death was appealed) it did not have a deterrent effect.
Had he been put to death, it definitely would deter a third murder.
I am a firm believer in the Just War theory. And in combat, one often has no time to sit down and consciously intend to kill the enemy; but if you shoot one and wound him, and he goes back to returning fire, you shoot again. And if necessary, again. That killing is justified; and I see the same issue here.
Many will disagree with me. Many of those have never been in combat. I have.
And I can appreciate the Pope’s decision to tighten up the issue; and you can talk all day to me about it, and I will maintain that in certain and limited circumstances, I would back the death penalty. John Paul’s comment about modern prison systems and the ability to contain the rage/hatred/insanity which drives certain murderers was not absolute, and this case is a prime example of it.
I am an absolute believer in the inherent right to self defense. To say that the State does not have that inherent right (as the State is not some disembodied figment of law, but rather the people within it) to self defense appears to be an oxymoron.