May 27, 2026 – San Bernardino County Sheriff’s Department officials report that on Friday, May 8, 2026, deputies in Rancho Cucamonga responded to a hospital where the victim was receiving treatment for injuries sustained in a physical assault. Through investigation, deputies learned that two days prior, on Wednesday, May 6, 2026, at about 8:46 a.m., Ricardo Castanon rode a bicycle northbound in the Best Buy parking lot when a male subject physically assaulted him. Castanon was seriously injured and transported to the hospital by a family member.  

Castanon remained hospitalized, and his condition worsened. Castanon succumbed to his injuries on Saturday, May 23, 2026. The Sheriff’s Specialized Investigations Division – Homicide Detail assumed the investigation.

Homicide detectives responded to the Rancho Cucamonga Police Department and, after further investigation, identified the suspect as Walter Maurice Jackson, who was known to Castanon.   

On Sunday, May 24, 2026, at about 6:44 p.m., Jackson was seen walking near Church Street and Elm Avenue and was contacted by Rancho Cucamonga deputies. Jackson was arrested for PC 187 – Murder and booked at the West Valley Detention Center, where he remains without bail. 

Anyone with information related to this case is asked to contact the Homicide Detail 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: May 6, 2026
INCIDENT: PC 187 - Murder
LOCATION: 12260 Foothill Boulevard, Rancho Cucamonga
SUSPECT(S): Walter Maurice Jackson, 46-year-old Male Resident of Rancho Cucamonga
VICTIM(S): Ricardo Castanon, 57-year-old Male Transient of Rancho Cucamonga
Refer: Detective Javier Lopez or Sergeant Bryan Sprague 
Station: Homicide Detail
Phone No. 909-890-4904
Case No. DR# 112605102 / H# 2026-053

Source: San Bernardino County Sheriff’s Department