Marin County, CA – In June 2025, Detectives from the Marin County Sheriff’s Office Specialized Investigative Unit (SIU) initiated a follow-up investigation into a suspected opiate overdose involving a victim in San Rafael. The investigation led to the identification of a suspect and the subsequent issuance of a search warrant by a Marin County Superior Court Judge.
On July 2, 2025, at approximately 2:00 PM, SIU Detectives executed the search warrant at a residence on Old Adobe Road in Petaluma, resulting in the arrest of 46-year-old Michael Maffei.
Maffei, a convicted felon, was taken into custody on multiple felony charges, including:
• Felon in possession of a firearm
• Furnishing a controlled substance causing great bodily injury
• Various narcotics and firearms-related offenses
Maffei was booked into the Marin County Jail and is currently being held without bail.
The Specialized Investigative Unit (SIU) is a multi-agency task force comprised of detectives from law enforcement agencies throughout Marin County. SIU focuses on narcotics-related investigations and remains committed to protecting the community by aggressively pursuing individuals who distribute dangerous and illegal substances.
