" filing misdemeanor criminal charges in juvenile court with a pre-arranged deal where they charges would be dismissed and the arrest expunged within 1-2 years would not be inappropriate."
What the hell are you smoking? It's a stupid classroom prank. Nothing that deserves to be called a crime happened here.
If you cage kids up for 6 hours a day, they're going to test the fences. This is healthy and natural. Well, testing the fences is. The forced incarceration, not so much.
And who cares if it ever happens again?