If justice has already determined that their life is forfeit with no course of action to lighten punishment, then I would say death by firing squad is much more humane than a slow expensive ride to death where you have no freedom outside of your own mind and even that gets twisted by your environment. Would you also go on to trumpet a cause against putting down dangerous dogs and instead seek to have them caged up for the rest of their lives?
Prison is not about rehabilitation it's about punishment so them coming to peace with themselves is totally irrelevant. Revenge fuels a lot of prison sentences.
All good that comes of prison is totally unrelated to how the prison system and justice system is set up.
Basically this, the courts have already taken his life away from him. At least do it in a humane and efficient way.
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