Allegheny County detectives say the suspect was walking out of Aprimo Pizza in Mount Oliver with the money he had just stolen, when he turned around to say, "Have a good night," before he fled.
Before his polite exit, police say the man wasn't so nice. He held a gun to one employee's back while screaming for another to open the cash register drawer.
He left after stealing an undetermined amount of money. Nobody was hurt.
CBS Pittsburgh report that another pizza place in the same neighborhood was robbed twice in a week, most recently by an armed gunman on Sunday Dec. 2.