June 7, 2025 – DELANO, CA – California Department of Corrections and Rehabilitation (CDCR) officials are investigating the June 6, 2025, death of an incarcerated person at Kern Valley State Prison (KVSP) as a homicide. 

At approximately 10:30 a.m., incarcerated person Mario Renteria allegedly began striking incarcerated person Julian Mendez. Staff immediately responded with orders to get down, but the men failed to comply. Chemical agents initially stopped the attack, but more than 30 additional incarcerated people rushed Renteria and began striking him. Orders to stop were ignored and staff used multiple blast grenades to quell the violence.

Mendez received multiple wounds and life-saving measures were immediately performed. Mendez was taken to KVSP’s Triage and Treatment Area where a doctor pronounced him deceased at 11:05 a.m.

An improvised weapon was found at the scene.

Renteria remains in restricted housing pending investigation into this case. Officials have limited population movement to facilitate the investigation being conducted by KVSP’s Investigative Services Unit, and the Kern County District Attorney’s Office. The Office of the Inspector General was notified, and the Kern County Coroner will determine Mendez’s official cause of death.

Mendez, 46, was received from Riverside County on Dec. 2, 2004. He received a condemned sentence in 2002 for the first-degree murder of two teenagers.

Renteria, 36, was received from Riverside County on April 27, 2022. He was sentenced to life with the possibility of parole for first-degree murder (a third strike offense) and arson.

KVSP opened in 2005 and houses over 3,100 minimum and high-security custody inmates. KVSP offers academic classes and vocational programs and employs approximately 1,500 people.

Source & photos: CDCR