Please suggest where I can find reliable facts and statistics regarding the conditions in US prisons including violence and rape. Thank you.
Then start reading literature from Amnesty International: http://www.amnesty.org/
Despite what people think, AI isn't about any kind of "liberal agenda", they're just about wrongful imprisonment, torture, and basic human rights.
That'll get you started in statistics, and then you can start looking for the various Dept. of Correction websites in each state to see what initiatives they have, and you might even be able to get at their stats (although usually you have to ask or FOIA to get them).