August 13, 2024 – San Bernardino County Sheriff’s Department officials report that on Monday, August 12, 2024, at approximately 5:32 a.m., deputies from the Rancho Cucamonga Station were requested to respond to the 8700 block of Vivero Street regarding a person threatening to shoot himself.

Upon arriving, deputies contacted Mark Anderson by phone in an attempt to have him exit the house unarmed and receive help, however, Anderson refused. Shortly after 6:00 a.m., Anderson exited the house with a rifle. Deputies continued their attempts to negotiate with Anderson without success and Anderson shot himself. He was pronounced deceased at the scene.

Detectives with the Sheriff’s Specialized Investigations Division responded and have assumed the investigation.

Anyone with information about this case is asked to contact Detective Francisco Demara, Specialized Investigations Division, at (909) 890-4904. Callers can remain anonymous and contact We-Tip at 800-78CRIME or www.wetip.com.

DATE/TIME: August 12, 2024 / 5:32 a.m.

INCIDENT: In-Custody Death Investigation

LOCATION: 8700 Block of Vivero Street, Rancho Cucamonga

DECEDENT(S): Mark Anderson, 64-year-old Male, Resident of Rancho Cucamonga

Refer: Detective Francisco Demara or Sergeant Nicolas Craig

Station: Specialized Investigations Division

Phone No. (909) 890-4904

Case No. DR# 112408931 / H#2024-079

Source: San Bernardino County Sheriff’s Department