Where does the law step in?

I am just curious if anyone has ever called the police on a patient for threatening them or hitting them. Some patient's are of mentally sound mind yet still swing at nurses and hit them and I am wondering if they can be prosecuted for assault or battery.
Nurses certainly are allowed to press charges against patients who have assaulted or battered them. In fact, many nurses already have pressed charges against patients who have assaulted or battered them.The customer who punches the waitress at the pancake restaurant is usually going to get arrested. The AOx4 patient who punches the nurse really needs to get arrested, and management needs to stop sweeping these types of incidents under the rug.