If they deserve to rot in prison, they should rot in prison. If they deserve to be realeased at the age of 70 or 80 they should be released.
You should be carefull with:
1. Masterminds & gang-bangers. They may not become less dangerous with age if they can still use their brains. Revenge might be served cold.
2. If you inprison an "intellectual" for life, do not give him a pencil and a paper. A man who has nothing to loose and has only his intellect to rely upon is even more dangerous in prison. If a "writer" is arrested, take the writing away from him, do not let him write anything. If he does write anything, burn it. The only permissible material should be anti-criminal romances or a sincere mea-culpa.
How about installing public floggings for Yobs? They're all about "respect" and creating an image aren't they? Unless there is a more humiliating punishment. Sew them tight inside a Teletubby costume or something.
Hello, I threw snowballs at STEED and now I have to wear this for 2 months or face 6 in the brig, having my ass raped three times a day because I have to call for more saying "Again! Again!".