Police have arrested a Berkeley man on suspicion of numerous firearms-related allegations. Photo: BPD

A traffic stop in West Berkeley over the weekend put a Berkeley arborist in jail on suspicion of a slew of firearm-related violations, authorities report.

Police said they pulled the man over Saturday just before midnight at Sixth Street and University Avenue. During the traffic stop, said Berkeley Police spokesman Officer Byron White, the officer realized the vehicle had a license plate on it that did not belong to it.

Police searched the driver, identified as 36-year-old Arturo Frisch Avila, and found a loaded handgun in his waistband: “Inspecting the handgun further, the officer noted that the firearm was homemade (unregistered, no serial number) from a polymer,” White said in a prepared statement in response to a Berkeleyside inquiry.

During a vehicle search, police said they also found what they described as the “upper assembly,” or portion, “of an assault rifle,” methamphetamine and other weapons.

BPD arrested Avila in connection with carrying a concealed loaded firearm, possession of a loaded unregistered firearm and possession of controlled substances while armed.

As the investigation continued, White said, police ultimately searched Avila’s home and found high-capacity rifle magazines, which are illegal to purchase, ammunition and another handgun.

BPD also arrested Avila in connection with the high-capacity magazine, White said. As per state law, California gun owners may not legally purchase magazines that can hold more than 10 rounds of ammunition.

Avila remains in custody at Berkeley Jail with a bail of $147,500, according to court records online.

He is set for arraignment Wednesday morning at the Wiley Manuel Courthouse in Oakland.

On his LinkedIn page, Avila describes himself as a “Tree Climber, child educator, and appreciator of life.” He has been a capoeira instructor for nearly 20 years and has worked as an arborist since 2011, according to the page.

“All debris that can be accepted by the Oakland Zoo will be donated to their elephants/giraffes,” he writes on the page, providing detail about his tree pruning work. “Fire wood collected and large trunks saved for drum making/art and local wood carvers. Keeping in mind how long it took to grow brings patience and love to what I do. Walk in balance. Peace.”

Emilie Raguso (former senior editor, news) joined Berkeleyside in 2012 and covered politics, public safety and development until her departure in 2022. In 2017, Emilie was named Journalist of the Year...