South Valley inmate who was serving a life sentence is killed on prison yard

Officials at Kern Valley State Prison (KVSP) in Delano are investigating the death of an inmate who was killed Thursday in a recreational yard.

According to officials, correctional officers were responding to two inmates — Matthew Thornton and Michael Arzaga — attacking another inmate Robert Hargrave with a manufactured weapon at the Facility B recreational yard.

Hargrave, who serving life without the possibility of parole for first-degree murder, suffered multiple stab wounds to his back, chest and abdomen.

He was taken to the institution’s triage then transported to an outside hospital for treatment, where he was pronounced dead.

Officers had to use chemical agents to stop the attack. It was not immediately clear what prompted the attack.

Hargrave had been in prison since May 1994, admitted from Riverside County.

The KVSP Investigative Services Unit and the Kern County Sheriff’s Office are investigating.