San Diego County sues Polymaker over 3D-printed ghost gun filament

San Diego County, in collaboration with the Giffords Law Center, has filed a lawsuit against Polymaker, a manufacturer of 3D printer filament. The suit alleges that the company made a strategic business choice to market and sell polymer filament to Californians specifically for the purpose of manufacturing illegal, untraceable “ghost guns.”

The legal action seeks restitution of profits, civil penalties, and injunctive relief. While the PLA filament itself is not illegal, the lawsuit focuses on how the product is promoted. Prosecutors argue that Polymaker targeted the firearm-manufacturing community, citing the hiring of Sean Aranda—a prominent figure in the 3D-printed weapon community known as “The 3D Print General”—as evidence of this intent.

The complaint highlights that consumer-grade 3D printers and filament allow for the rapid production of functional firearms. The suit references an incident where the San Diego Police Department’s Ghost Gun Team recovered filament and printed parts from a 16-year-old’s workshop, which authorities believe was intended for illegal sale.