this kind of behavior (who had first hand knowledge that it was going on) as part of the problem. Maybe not criminally liable, but still participating in a cover up.

This goes beyond what your own child experiences. This is criminal behavior and must not be tolerated in a civilized society. Go read “The Kite Runner” if you need a reference for what happens when sexual assault is normalized or “boys will be boys” justification rules the day.

This must not stand. If the OP wants me to approach the principal, district officials, or the police to report this, I will gladly do so.