News Releases

High Desert State Prison Investigating Inmate Death as a Possible Homicide

SUSANVILLE – High Desert State Prison officials are investigating the death of an inmate as a homicide after two other inmates attacked him.

On Jan. 27 at 2:29 p.m., staff saw inmates Jose R. Castillo and Victor M. Zapien attack inmate Richard Prieto on the Facility D yard.

Officers immediately responded by issuing a warning shot and using chemical agents to quell the incident.

Prieto, 44, suffered multiple puncture wounds to his chest, back, head and neck. Responding staff transported him to the prison’s medical facility and life-saving measures were given. A doctor pronounced Prieto deceased at 3:02 p.m.

Officers recovered two metal inmate-manufactured weapons at the scene. No staff members were injured in the altercation.

Castillo and Zapien have been placed in segregated housing pending an investigation into their involvement.

The Lassen County District Attorney’s Office is assisting HDSP’s Investigative Services Unit. The Office of the Inspector General has been notified.

Prieto was received by San Joaquin County on March 31, 1994. He was sentenced to 22 years for attempted second-degree murder with enhancements of personal use of a dangerous or deadly weapon and inflict great bodily injury.

Castillo, 26, was received from Sonoma County on May 6, 2014. He was sentenced to six years for assault with a deadly weapon on a peace officer/fireman and while in prison was sentenced to an additional six years for possession/manufacture of deadly weapon by a prisoner.

Zapien, 31, was received by Stanislaus County on July 8, 2014. Zapien was sentenced to life with the possibility of parole for first-degree murder.

HDSP, located in Lassen County, opened in 1995 and houses 3,145 minimum-, medium-, and maximum-custody inmates. The prison provides academic classes, vocational instruction, work assignments and rehabilitation programs and employs more than 1,200 people.

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