County man faces drug, firearm charges after police search
Detectives discover methamphetamine and weapons at two residences
– A San Luis Obispo man was arrested on multiple charges related to firearms and drug possession after an investigation by the San Luis Obispo Police Department.
On June 23, 2025, a resident of the 1400 block of Phillips Lane reported to police that their neighbor, later identified as James Mattison, had approached them in the apartment complex parking lot holding a shotgun two weeks earlier. The resident also reported that Mattison again approached them on June 20 in the building’s laundry room while holding a shotgun, stating he was concerned someone might break into his car. Mattison then returned to his apartment.
Detectives quickly filed for a Gun Violence Restraining Order (GVRO), which was approved later that day. The GVRO is a temporary order that prohibits the possession, purchase, or ownership of firearms, firearm parts, ammunition, magazines, and body armor. The order is reviewed by a judge at a later date to determine if it should be extended or dismissed.
At 11:02 p.m. on June 23, SLOPD dispatch received a call reporting domestic violence. The caller, identified as Mattison, stated he could no longer hear anything but would be in front of his parents’ home on Clover Drive. Officers located Mattison at the Clover Drive location, detained him, and served him with the GVRO. Mattison claimed he did not have any firearms at his Phillips Lane residence but stated that he had two guns at the Clover Drive home, which were surrendered to the officers. Mattison also consented to a search of his vehicle and residence. During the search of his car, officers found an unloaded handgun magazine.
The following morning, detectives obtained a search warrant and went to Phillips Lane to search Mattison’s residence. There, they discovered several containers of suspected methamphetamine, scales, glass pipes, multiple firearms, parts of non-serialized firearms created by a 3D printer, and ammunition. A subsequent search of Mattison’s bedroom at the Clover Drive home yielded a 9mm handgun, a non-serialized “ghost” firearm, more suspected methamphetamine, ammunition, and two additional 3D printers.
Mattison was arrested and booked into the San Luis Obispo County Jail on charges including felony possession of a controlled substance for sale, felony possession of a controlled substance, felony possession of a loaded firearm while committing a felony drug violation, felony possession of a controlled substance while in possession of a firearm, misdemeanor possession of an un-serialized firearm, and misdemeanor manufacturing or assembling a firearm.
Detectives requested a bail enhancement, which was granted, setting Mattison’s bail at $350,000. On July 2, 2025, Mattison was released under the Post Arraignment Monitoring Program.
