Contra Costa authorities investigate in custody death of Rio Vista woman at West County Detention Facility

Martinez, California – Authorities have launched an investigation after a 59-year-old inmate was found unresponsive inside the West County Detention Facility early Friday morning, prompting the activation of the county-wide protocol for in-custody deaths.

According to the Contra Costa Sheriff’s Office, the incident occurred on Friday, July 10, 2026, at approximately 12:24 a.m. during a routine safety check inside the detention facility.

A deputy sheriff conducting the inspection discovered an inmate who was unresponsive and had a ligature around her neck.

County-wide protocol activated following inmate’s death

Deputies immediately began life-saving efforts while medical personnel from the facility’s Health Services unit responded to assist. Emergency responders from the local fire department and ambulance service also arrived at the detention facility to continue resuscitation efforts.

Despite those attempts, the inmate was pronounced dead at the scene.

The Contra Costa Sheriff’s Office identified the woman as Robi Lynn Perley, 59, of Rio Vista.

Authorities said Perley had been taken into custody the previous day by the Antioch Police Department. She had an outstanding arrest warrant related to driving under the influence and a probation violation.

After her arrest, she was booked into the Martinez Detention Facility at approximately 1:30 p.m. before later being housed at the West County Detention Facility.

Following the death, officials activated the county-wide law enforcement involved fatal incident protocol, which is used to ensure an independent and coordinated investigation into deaths involving law enforcement or while a person is in custody.

The investigation is being conducted jointly by the Contra Costa Sheriff’s Office and the Contra Costa County District Attorney’s Office.

Authorities have not released additional information regarding the circumstances surrounding the death while the investigation remains ongoing.

Officials are asking anyone who may have information related to the incident to contact the Contra Costa Sheriff’s Office Investigation Division at (925) 313-2600. Anonymous tips may also be submitted by email at [email protected] or by calling (866) 846-3592.

Investigators said the case remains active as they work to determine all of the circumstances surrounding the inmate’s death.