This becoming public knowledge, whatever this is, is NOT the case. That Sandusky was investigated previously and the DA did not charge him was apparently public knowledge.
There will be two cases if this goes to trial. The state will present its case. The defense will present its case for defense. Then the trier[s] of fact will decide. So far you have only heard a small part of the governments version and they presume him guilty or they would not charge him.
Whether it was a matter of public record or not is not the issue. It was certainly not a national news story or common knowledge, therefore your statement made no sense in context.