Traffic stop in Arroyo Grande leads to arrest for drugs, guns, explosives

October 21, 2025

By KAREN VELIE

A traffic stop in Arroyo Grande last week led to the arrest of a 64-year-old man after deputies found narcotics and a firearm inside the vehicle.

Shortly after 3 a.m. on Oct. 17, San Luis Obispo County sheriff deputies stopped a vehicle on the 600 block of Mesa View Drive in Arroyo Grande. During the stop, deputies discovered paraphernalia, drugs and the firearm in the vehicle driven by Michael Rosso.

After obtaining a warrant, deputies searched Rosso’s residence on the 600 block of Ralcoa Way in rural Arroyo Grande. Deputies seized multiple firearms, narcotics, and an improvised explosive device.

The San Luis Obispo County Bomb Task Force was immediately called to the scene to properly remove and dispose of the explosive devise.

In total, the investigation resulted in the seizure of three firearms, approximately 6.3 ounces of suspected methamphetamine, and one improvised explosive device.

Deputies booked Michael Rosso in San Luis Obispo County Jail on charges of felon in possession of a firearm and ammunition, possession of a destructive device, possession of a controlled substance for sale, armed with a firearm during commission of a felony, and possession of drug paraphernalia.