Authorities are investigating the death of an inmate at California State Prison, Sacramento as a homicide.
According to prison officials, 49-year-old John Cisneros was found unresponsive in his cell at approximately 9:15 p.m. on Feb. 23, 2026. Staff attempted life-saving measures, but he was pronounced dead at 9:59 p.m.
His cellmate, 34-year-old Irvin Sanchez, was removed from the shared cell and placed in restricted housing pending the outcome of the investigation. The Sacramento County District Attorney’s Office and the prison’s investigative unit are reviewing the case. The Office of the Inspector General has also been notified.
Cisneros had been received from Los Angeles County in 2015 and was serving a sentence for robbery, along with additional sex crime convictions incurred while incarcerated.
Sanchez was admitted to the prison system in 2013 and is serving time for attempted second-degree murder and firearm-related offenses.
Officials said the investigation remains ongoing and no further details have been released.
