LEXINGTON, Okla. (AP) — The Oklahoma Department of Corrections says a man serving life in prison for stabbing his parents and three siblings to death tried to attack prison staff with an 8-inch long "sharpened instrument."

A DOC report first obtained by the Tulsa World says 22-year-old Robert Bever approached two staff members from behind in a dayroom at the Joseph Harp Correctional Center on July 15. One grabbed him and he complied with orders to drop the weapon and drop to the ground.

DOC spokesman Matt Elliott said Wednesday that no one was seriously hurt and charges are unlikely.

Bever ple...