[liquidben]

I'd presume that trespass would apply to this situation, although it would not likely invalidate the lawsuit outright.

[Periodic]

That's the thing. As a public school, at least in our area, you're allowed to be on the grounds when the school isn't open. You just can't go inside.

I once was ticketed for being at a park after sunset in our town. The cop explained to my friends and I that if we had just been across the street at the elementary school then it wouldn't have been a problem.