Business Issues: Angry Customers Who Won't Calm Down

My question involves business law in the state of: PA



My question involves legal process for employees in retail situations who have to deal with irate or possibly violent / unstable customers.

At what point in such an interaction does an employee have the right to ask a customer to leave the premises? ?

Or does only the owner or assigned manager have this right?

Someone I know was very upset about an apparent customer service issue at a store. This person went to the store and hollered at the employees, used foul language, refused to calm down even when he was told to calm down by the employees or he would have to leave. One of the employees called the police on this person. The police showed up, and asked the person to leave the building. This person is now possibly considering legal action against the store because they don't think the employees had any right to ask him to calm down or leave the store, since he was a customer there.

I'm thinking this person is wrong is assuming this, but what are the actual laws about this? Is this person correct in their assumptions?

Business Issues: Angry Customers Who Won't Calm Down