I've got news for you. The chances of "innocent" prisoners being in one of those prisons is practically zero and nil - and "nil" is winning.
These killers are well-vetted before they even get the chance of being an honored guest in one of these places.
Shed not a tear for any of these vicious murderers. You're wasting your time and your tears. Shed them instead for their tortured, dead victims. Rather, just pray they never again see the light of day - especially in your neighborhood or the neighborhood of somebody you love!
You are assuming to know things that only God can know.