The police only knows how to issue traffic tickets. To go to their homes was a bad idea. Contact media and give the names of the parents. I’m sure that one of the local stations ,hungry for news, will do that. Make sure to print out copies from Facebook page, police report. If you can afford few hundred extra dollars, have an attorney send letters to parents, police dept. and Facebook indicating that, if God forbid, something happens to your child, all of them will held criminally responsible. It will work. Been there, done that.
Good thinking!