You have an number of teens wandering somewhere they don't belong at night, I think the teacher overreacted but doesn't need to be charged. I also thing the police overreacted and should charge the kids with tresspassing.
"My home is my castle" is called constitutional rights dude; get over that. You don't want the right to live safely in your own home cool!!! Invite the neighborhood thugs to your house; we'll see how long that lasts