West Valley Detention Center: In-Custody Death Investigation 

April 21, 2026 – San Bernardino County Sheriff’s Department officials report that on Sunday, April 19, 2026, at around 4:55 a.m., deputies assigned to the West Valley Detention Center were alerted to an inmate who was found unresponsive. Deputies immediately rendered aid along with jail medical staff. Medical personnel initiated lifesaving measures until personnel from American Medical Response and Rancho Cucamonga Fire arrived, who also attempted resuscitation. Mays was pronounced deceased at the scene.    

The Sheriff’s Specialized Investigations Division – Homicide Detail responded and assumed the investigation. It was found Mays was originally arrested and booked at the High Desert Detention Center on Tuesday, March 24, 2026, by the Adelanto Sheriff’s Station on a PC 245(A)(1) warrant. Mays was later transferred to West Valley Detention Center on Tuesday, April 14, 2026, where he was housed. Mays did not have obvious signs of trauma. His cause and manner of death will be determined after an autopsy. 

The investigation remains ongoing, and no further information is available currently.

Anyone with information about this case is asked to contact Detective Jacob Angelini Specialized Investigations Division at 909-890-4904. Callers wishing to remain anonymous should call or text “REPORT” to We-Tip at 844-909-3006.  Online reporting is also available at https://mobile.catapultems.com/sbcsd/Sites.

DATE:  April 19, 2026, at approximately 4:55 a.m.
INCIDENT: In Custody Death Investigation
LOCATION: West Valley Detention Center, Rancho Cucamonga
DECEDENT: Mariel Mays, 26-year-old male, Resident of Adelanto
Refer: Detective Jacob Angelini or Sergeant Bryan Sprague 
Station: Homicide Detail
Phone No. 909-890-4904
Case No. DR# 342601076 / H# 2026-042

Source: San Bernardino County Sheriff’s Department