Edmond post office shooting

The Edmond post office shooting occurred in Edmond, Oklahoma on August 20, 1986. During a deadly rampage that lasted less than fifteen minutes, postal worker Patrick Sherrill pursued and shot twenty coworkers, killing fourteen of them, before committing suicide. Sherrills attack inspired the American phrase going postal.

Patrick Henry Sherrill was born in Watonga, Oklahoma and had served in the United States Marine Corps. He was considered an expert marksman and was a member of a National Guard pistol team.

Source: Wikipedia