We have had issues also at our Spokane haunt, however seem to be able to keep most of it under control with a moderate security staff. If an actor is touched or we notice someone messing with props, they are immediately escorted out the exit. The worst thing we have expierienced is someone pulling a gun in the qeue line the cops showed up within minutes. I believe the best way to handle this is by training your security staff or hiring off duty coppers.
EVIL IS AS EVIL DOES I ALWAYS SAY!