A missed storage payment unraveled the whole operation.
Inside a garage on Roy Avenue, near the quiet southeastern edge of San Jose's Willow Glen neighborhood, investigators found what amounted to a small factory: eight assault rifles, piles of rifle parts, three partially assembled machine pistols, ammunition, 3D printers, and an undisclosed quantity of fentanyl. The people who lived and worked there, prosecutors say, had been building guns to order — untraceable, unserialized, delivered to customers who assembled the final product at home.
On Thursday, February 17th, investigators from the Santa Clara County District Attorney's Office, working alongside San Jose police, the county sheriff's department, and federal ATF agents, executed search warrants at two South Bay addresses. The first was the Willow Glen home shared by Jack Michael Mahon, 38, and Amanda Mary Bazzani, 32. The second was an apartment in Morgan Hill belonging to Joseph Clifford Cahoon, 31.
The DA's office announced charges the following Tuesday. Mahon faces the most serious legal exposure: 28 felony counts, including illegally manufacturing assault weapons and possessing firearms as a convicted felon, with a drug charge added for the fentanyl found on the property. Cahoon was charged with seven felony counts on similar weapons grounds. Bazzani was not accused of manufacturing anything, but faces one felony count each for possessing a rifle and possessing ammunition while having a prior felony conviction.
Prosecutors say the operation centered on made-to-order AK and AR-style rifles, built using component kits, custom fabrication tools, and 3D printing technology. Mahon is also accused of converting at least one pistol to fire fully automatically — a federal crime on its own. Customers reportedly arranged purchases online and received weapons with no serial numbers and no background checks required, leaving final assembly to the buyer.
The investigation began not with a tip or a traffic stop, but with an unpaid storage bill. In December, a Morgan Hill storage facility placed Cahoon's rental unit in default after he stopped paying. When the company inspected the unit, they found signs it had been broken into — and surveillance footage showed Cahoon sneaking back onto the property. Morgan Hill police obtained a search warrant and found the unit had been hastily cleared out, but what remained told a story: a welding table, cutting tools, Dremel tools, 3D printer components, printed renderings of an AR-15 lower receiver, metal pieces cut in the shape of a MAC-style firearm receiver, a handgun grip, a loose bullet, and an assortment of tools suited to building or assembling illegal firearms.
That storage unit find opened the door to the wider investigation. By the time warrants were served in February, Cahoon was already being sought by police in a separate case — he was allegedly running another gun-manufacturing operation out of a motel room in Gilroy. At his Morgan Hill apartment, investigators recovered 3D printers, an unserialized AR-style lower receiver, an incomplete AK-47 shell, related parts, and a drill press.
Most of the weapons and manufacturing equipment at the Willow Glen address were concentrated in the garage. A Los Gatos address was also searched as part of the investigation, though details about what was found there had not been released at the time of the announcement.
District Attorney Jeff Rosen framed the arrests as part of a broader effort to disrupt the supply chains feeding ghost guns into the region, describing the problem as one that grows one illegal part at a time. The case now moves toward prosecution, with three defendants facing a combined 36 felony counts — and a fourth location still yielding undisclosed details.
Notable Quotes
Ghost guns are swamping our community, illegal part by illegal part. We are working tirelessly to dismantle these criminal networks.— Santa Clara County District Attorney Jeff Rosen
The Hearth Conversation Another angle on the story
What made this operation different from someone just buying a gun illegally?
The whole point was to manufacture them — build rifles from parts, use 3D printers to fabricate components, and sell them with no serial numbers. There's no paper trail, no background check, no way to trace the weapon after it leaves.
How did investigators even find it?
A missed storage payment. Cahoon stopped paying rent on a unit in Morgan Hill, the facility put it in default, and when they checked it, they found it had been broken into. Surveillance caught him sneaking back in. That one thread unraveled the rest.
What does it mean that customers assembled the weapons themselves?
It's a legal gray area that ghost gun operations exploit. If you sell someone a kit of parts, you can argue you didn't sell them a gun. The buyer does the final assembly at home. No background check required, no serial number attached.
The fentanyl charge against Mahon — does that change the nature of the case?
It complicates the picture. It suggests the garage on Roy Avenue wasn't just a gun shop. Whether the drugs and the weapons were connected businesses or just coexisting under one roof, prosecutors will have to establish that.
Cahoon was allegedly running a separate operation out of a Gilroy motel room. What does that tell you?
That he wasn't a hobbyist. Someone running manufacturing out of a storage unit, an apartment, and a motel room is treating this as a business with multiple production sites.
What's the significance of 3D printing in all of this?
It lowers the barrier to entry dramatically. You don't need a machine shop. You need a printer, the right files, and some basic tools. The renderings they found in the storage unit show someone was designing parts, not just downloading them.
Is this case unusual, or is it part of a pattern?
The DA's statement suggests it's a pattern. The phrase 'illegal part by illegal part' isn't describing one garage — it's describing a supply chain problem that law enforcement is trying to dismantle piece by piece.