If my fiancé is injured jumped or stabbed in prison and tells the guards and they tell him they don't care, can he sue the prison?

The short answer is "no", but there are circumstances we have heard where guards acted as "look-outs" so that a fight could happen. If that were proven true, there might be a lawsuit an attorney might take on. But, we are not attorneys. An inmate can start by filing grievances with the administrative staff. We encourage him to copy all correspondence to someone on the outside to have a "paper trail" of their concerns. If he was not injured too badly, we might even let it go. If there was a stabbing, it must be reported to the medical staff.