Teen Arrested In Rohnert Park 3D 'Ghost Gun'-Making Operation

ROHNERT PARK-COTATI, CA — An 18-year-old was arrested and charged following an investigation into a suspected illegal firearm-making operation.

Detectives with the Santa Rosa Police Department Gang Crimes Team searched an apartment on Tuesday in the 6900 block of Commerce Boulevard in Rohnert Park following an investigation into a suspected illegal firearms manufacturing operation.

Detectives detained the suspect, Mario Reynosa, 18, of Rohnert Park, when he answered the front door.

Detectives found a 3D printer, three 3D-printed pistol frames, two 3D-printed AR-15 lower receivers, various firearms parts, and 9mm ammunition, according to the Santa Rosa Police Department.

Reynoso was arrested and charged with failure to provide firearms records to the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives and unlawful firearms possession.

In 2024, the unit seized four 3D printers believed to be used to make privately manufactured firearms, commonly known as “ghost guns.”

In February 2024, Santa Rosa police arrested a high schooler suspected of having an unserialized firearm, being a minor in possession of a handgun, unlawful manufacture of a firearm, and gang enhancement, police said at the time.

According to police these guns are of particular concern to law enforcement agencies because they typically lack a serial number and are often unregistered, making them untraceable, thereby hindering investigations into crimes involving firearms. They also allow for people unqualified to have a gun to obtain firearms by circumventing the necessary background checks.

Under California law, individuals must be eligible to own or possess a firearm in order to manufacture or assembled their own —including through the use of 3D printing. They must also ensure that the firearm is legal to possess or manufacture in the state. California law prohibits individuals from manufacturing or assembling certain classes of firearms, including assault weapons and machine guns. Additionally, California law generally prohibits the manufacture of unsafe handguns. A self-manufactured handgun must meet certain design features under state law. A self-manufactured semiautomatic handgun, even if temporarily altered for single-shot firing, must include safety and security features. And serial numbers are required for self-made firearms.

The Gang Crimes Team is a unit of four plainclothes detectives and one sergeant tasked with addressing gang-related incidents, according to the Santa Rosa Police Department.