You're kidding, right? Cruel and unusual? He's never been punished AT ALL -! For organizing, leading, and carrying out a triple murder.
Even the son of the one holdout juror in 1967, the one who hung the jury (setting Killen free) said that his mother later admitted she was wrong, and sorry she let him off. It was 11-1 to convict him.
I'm not a fan of seeing people live without consequences; even knowing that the real judgement - for each of us - comes beyond this life.
You're right of course, but there comes a time when it's too late to do much good. Have fun putting a sick old man in prison. That really does your cause a lot of good.