Other Injuries: Battery of a Minor

My question involves injury or loss that occurred in the state of: Pennsylvania.

My son was in a program for high schoolers at a university in Pennsylvania in 2005. Recently, I found a video on his computer of what appeared to be him being punched in the face. When I asked him about this incident, he explained that his RA (resident adviser) got into a fight in the dorm rooms one night and when my son attempted to separate them, his RA "accidentally" punched him in the face. He was told to stay quiet unless asked and the RA explained what he did to a "disciplinary board". The RA was reprimanded and taken out of the dorms, but I was never contacted about this incident or notified at all. My son was 16 at the time and the RA was 21.

I approached the university about this incident and there appears to have been no record of it whatsoever, I refuse to believe that an incident like this, with the RA being kicked out of the dorms would have no paper trail whatsoever.

Is there a way I can compel the university to give me a straight answer on what happened? They have been unhelpful and even hostile at times, I was told to "get a lawyer, we won't make your case for you".

I am just very frustrated that the university will not give me a straight answer to anything. If I were to retain legal counsel, is it possible I could compel them to give me a straight answer on what happened? Does a suit need to be filled for this to occur? If so, what would I sue for as it was my son who was punched and he is now an adult.