Is there anything at all we can do?

My son is home after serving a 14 month prison sentence on drug charges. He definitely changed a lot in there and not in a good way. He's almost 20 and I'm sad he has this on his record so young, but even more worried about him. He moved home with me and just seemed different. He had more anxiety and didn't really want to leave the house much. He knows he has to get a job soon, but he mostly stays in his room. I know prison can change people, but I felt like he needed someone to talk to so we talked and I asked if he was having a hard time adjusting. He didn't really want to talk at first, but then started talking about things that happened in prison. He told me he was put into solitary confinement for dumb reasons and had been sexually assaulted multiple times. At first I thought he meant prisoners were sexually assaulting him, but he told me he had been sexually assaulted by a guard! I don't understand how that could even happen ,don't they have camera's everywhere! I told him we needed to do something about it but he said its pointless. I'm friends with someone who is an ex felon and I asked her what we should do. She just said put him in therapy and that she's sorry but its really pointless to try to do anything legal. Apparently stuff like that happens all the time and the state doesn't care about criminals so it would just be a waste of money in court fees. Idk if there are any felons on here by any chance but is this true? My son made a mistake and drug charges are no excuse for guards to do something so disgusting😡 Be honest with me though, is there really nothing I can do?