I can validate your statement that prison has some 'seriously bad dudes'.

I used to live in a city with a federal penitentiary, I made friends with several people that worked there. One friend worded it this way: There are a some people that are just there due to circumstances, or bad choices, or whatever. Then there are some people there that will hurt you or anyone else just for the fun of it. You definitely want to avoid the mean ones, because there is no rhyme or reason to why they want to hurt you.