Okay, Let's All Calm Down. Way Down. Way, Way, Way Down.

 St. Peterburg Times

A Marine reservist armed with a tire iron beat and chased a man he thought was an Arab terrorist and even called 911 to say he was detaining the man, police said.
But the man he assaulted was actually a Greek Orthodox priest visiting from overseas who spoke limited English, police said.
...
Instead of offering help, Bruce struck the priest on the head with a tire iron, police said.