Does parent have rights to ask administrators to disclose the information of how the school handled investigation process in a students conflict?

My son was accused of something he didn’t do. The accusations were based on the words of other student that had previously physically associated my son. Principal assigned two days out of school suspension. When I asked to present me with some evidence they said that my son admitted it to AP. He didn’t admit to AP action that they are penalizing him for. Meanwhile after I addressed all my questions to them, they started changing out of school to in school suspension and the category of my son’s misconduct. Still no explanations.