Update: San Luis Obispo County jail death linked to fentanyl
Update posted April 4, 2026:
– The San Luis Obispo County Sheriff’s Office released additional information regarding the in-custody death of Trenidad Castilleja, 48, of San Luis Obispo.
The incident occurred March 14 at approximately 8:59 p.m. at the County Jail.
The Sheriff’s Office Coroner’s Unit determined the cause of death to be the toxic effects of fentanyl, with hypertensive cardiovascular disease identified as a contributing condition. The Coroner’s Unit ruled the manner of death accidental.
Officials said fentanyl is a potent substance that can be hazardous in small amounts and is odorless and tasteless in its pure form, making it difficult to detect. Authorities said investigators continue to examine how Castilleja obtained fentanyl while in custody.
No further information is available at this time.
Original story posted March 16, 2026:
Next of kin notified, investigation ongoing
Next of kin notified, investigation ongoing– An inmate died at the San Luis Obispo County Jail on the evening of March 14 after jail, and health staff recognized he was in medical distress during medication dispensing.
Custody and nursing staff immediately rendered medical aid and CPR until paramedics arrived. The inmate, Trenidad Castilleja, 48, of San Luis Obispo, remained unresponsive and was pronounced deceased by paramedics at approximately 8:59 p.m.
Castilleja was arrested by the San Luis Obispo Police Department on Dec. 18, 2024, and had been in custody on three separate cases. Two cases had been resolved, and he was pending sentencing on the third at the time of his death. Castilleja had a history of more than 24 bookings into the jail since 1998.
The cause of death is unknown pending autopsy. No foul play is suspected.
Next of kin has been notified. No further information is available at this time.
