California Medical Facility Officials Investigating the Death of an Incarcerated Person as a Homicide

California Department of Corrections and Rehabilitation officials are investigating the Jan. 12, 2026, death of an incarcerated person at the California Medical Facility (CMF) as a homicide.

On Jan. 4, 2026, at 7:20 p.m., staff responded to a physical altercation between incarcerated persons Joe Duty Jr. and Stephenson C. Kim in a housing unit. Kim was found unconscious and staff immediately responded, initiating life-saving measures on Kim and activating 911. Kim was taken immediately to the prison's triage and treatment area and subsequently transferred to an outside medical facility. Duty was medically evaluated and placed in restricted housing.

On January 12, an outside medical facility physician pronounced Kim deceased at 6:30 p.m.

Duty remains in restricted housing pending an investigation by the CMF Investigative Services Unit and the Solano County District Attorney's Office. The Office of the Inspector General has been notified.

Kim, 45, was most recently received from Orange County on May 23, 2012. He was sentenced to life without the possibility of parole for first degree murder and attempted first degree murder with enhancements for the intentional discharge of a firearm causing great bodily injury or death and the discharge of a firearm.

Duty, 30, was most recently received from San Joaquin County on Feb. 14, 2025. He was sentenced to 14 years for rape with force / violence / fear of a minor 14 years of age or older and lewd or lascivious acts with a child under 14 with force / violence / fear.

CMF was established in 1955 by the California Legislature to provide a centrally located facility to meet the medical, psychiatric, and dental health care needs of males incarcerated within CDCR. CMF is a medium-security medical facility located in the city of Vacaville in Solano County.

The majority of incarcerated patients at CMF reside in an outpatient setting and receive health care in outpatient clinics. Patients who require additional nursing care may be housed in the Outpatient Housing Unit (OHU). Patients who require 24-hour nursing care are housed in a licensed medical correctional treatment center (CTC). CMF also operates a 400-bed inpatient psychiatric CTC, a 50-bed mental health crisis bed CTC, and the first licensed prison hospice in United States.

Stephenson C. Kim (deceased)

Joe Duty Jr.