MOORPARK, Calif. — A 64-year-old equestrian trainer from Simi Valley is facing serious felony charges after law enforcement officials uncovered allegations of child sexual abuse linked to a local training ranch in Moorpark.
The suspect, identified as Marc Blumberg, was formally taken into custody on Thursday, July 23, 2026, following a multi-agency search warrant operation at his Simi Valley residence. Blumberg was booked into the Ventura County Main Jail on suspicion of committing lewd acts upon a child under 14 years of age, as well as an additional count relating to an illegal firearm transaction.
The joint arrest was executed by detectives from the Ventura County Sheriff’s East County Major Crimes Sexual Assault Unit, the Thousand Oaks Directed Enforcement Unit, and the Moorpark Police Station.
Initial Report Triggered Year-Long Major Crimes Investigation
According to official investigative details released by the Ventura County Sheriff's Office, the criminal probe originated in April 2025 when the Thousand Oaks Police Department received a call for service regarding an alleged sexual assault that had occurred several months prior, in October 2024.
The juvenile victim reported that she had been sexually battered by Blumberg while attending training sessions at MT Performance Horses & Cattle Company, a ranch facility located in the city of Moorpark where Blumberg provided professional equestrian instruction.
Following the initial outcry, specialized sexual assault detectives initiated a comprehensive, multi-month investigation into Blumberg’s activities and interactions at the training facility. Over the course of the inquiry, multiple witnesses stepped forward to describe similar unsettling or inappropriate encounters with the suspect at the ranch location.
Detectives eventually established sufficient probable cause to seek an arrest warrant and residential search warrant targeting Blumberg.
"On July 23rd, 2026, detectives from the East County Sexual Assault Unit, Thousand Oaks Directed Enforcement Unit, and Moorpark Detectives served a residential search warrant at Blumberg’s residence and arrested him," the Ventura County Sheriff's Office detailed in an official public notification.
Additional Weapons Charge and Search Warrant Discoveries
While executing the residential search warrant at Blumberg’s Simi Valley home, investigators uncovered physical evidence indicating that the suspect was involved in an unlawful weapons transaction.
As a result of those findings, detectives added an additional felony charge under California Penal Code Section 27545, which prohibits the unlawful transfer of a firearm without going through a licensed firearms dealer.
Following the search warrant service and property seizure, Blumberg was transported to the Ventura County Pre-Trial Detention Facility for formal processing on two primary felony counts:
- California Penal Code 288(a): Lewd or Lascivious Acts Upon a Child Under 14 Years of Age
- California Penal Code 27545: Unlawful Transfer of a Firearm
Detectives Appeal for Potential Additional Victims
Due to Blumberg’s longtime presence in the local equestrian community and his position as an instructor at MT Performance Horses & Cattle Company, investigators suspect there may be other individuals who experienced similar misconduct but have not yet come forward to law enforcement.
The Sheriff's Office released a public appeal encouraging anyone with information or additional reports regarding Blumberg to step forward:
"Due to the nature of this investigation, detectives believe there may be additional victims and encourage anyone with information to contact the Sheriff’s East County Sexual Assault Unit," department officials stated in the release prepared by Detective Robert Thomas.
Members of the public who have relevant information regarding Marc Blumberg or incidents at the Moorpark ranch are urged to contact Detective R. Thomas directly at (805) 371-8309 or via email at RobertG.Thomas@venturacounty.gov.
Those who wish to remain anonymous may submit tips through Ventura County Crime Stoppers by calling (800) 222-TIPS (8477). Crime Stoppers offers rewards of up to $1,000 for information that leads to an arrest and formal criminal complaint.