A correctional guard at North Kern State Prison was struck once by gunfire Monday night while working outside in a yard, authorities said.
The guard had been working in one of the yards about 7:45 p.m. when multiple shots rang out at the prison in Delano, said Ray Pruitt, spokesman for the Kern County Sheriff's Department.
He was hit once by the gunfire, which penetrated his stab-resistant vest, prison officials said. He was taken to a hospital, where he was treated for a minor wound.
"Our officers are dedicated to protecting public safety, and it is disturbing they are targeted in this way," said Secretary Jeff Beard of the California Department of Corrections and Rehabilitation.
Authorities believe an unknown gunman outside the prison walls fired rounds toward the yard.
Sheriff's deputies, SWAT officers, Delano police and the California Highway Patrol searched the prison and surrounding area but did not find the shooter.
Investigators have not identified any suspects, and a possible motive for the shooting has not been determined, Pruitt said.