3D printed firearms have become a growing concern for law enforcement in recent years. Lawmakers and online platforms have introduced new restrictions targeting both the weapons themselves and the digital files used to produce them. Now two states are attempting to push that strategy further upstream.
New York and Washington State are pursuing legislation to mandate “blocking technology” on 3D printers to address ghost gun production. However, open-source hardware company Adafruit Industries contends the approach is technically flawed. The company argues it could damage education and innovation while doing little to stop actual criminals.
Both bills take a similar approach. New York’s S.9005/A.10005 and Washington’s HB 2321 would require all 3D printers and CNC machines to scan files against a “firearms blueprint detection algorithm” and refuse to print flagged designs. The proposals respond to ghost guns, those unserialized firearms increasingly recovered in criminal investigations.
High-profile cases like the killing of UnitedHealthcare CEO Brian Thompson, in which prosecutors allege the suspect used a 3D printed firearm and suppressor, have intensified pressure for legislative action.
Governor Kathy Hochul and Manhattan District Attorney (DA) Alvin Bragg have framed the measures as necessary public safety interventions, with the DA calling the rise in 3D printed firearms a “growing threat.”
On paper, the legislative intent is straightforward: create barriers to illegal weapon production. Whether the approach is technically viable is another question entirely.
You Can’t Detect Intent from Shapes
Adafruit’s core argument centers on a classification problem. “You cannot reliably detect firearms from geometry alone,” the company stated in its analysis.
Any algorithm designed to flag gun parts would need to distinguish weapons components from countless legitimate objects that share similar geometric properties. For instance, pipes, tubes, blocks, brackets, wheelchair parts, prosthetics. All could trigger false positives.
Even federal prosecutors have acknowledged this ambiguity. Assistant U.S. Attorney Todd Greenberg described a Washington ghost gun case where the defendant “had a drill press, milling tools, and a 3D printer. It was all legally obtained. It’s all the tools that one might use for different manufacturing operations.”
Washington’s bill requires printers be engineered to resist bypass by users with significant technical skill. It also mandates a “preprint authentication” protocol. Adafruit argues such mandates would effectively force cloud-connected, vendor-locked subscriptions.
Moreover, open-source projects like Marlin, Klipper, and RepRap, all maintained by volunteer developers, would face compliance challenges. Offline machines, custom slicers, and parametric designs generated at print time would be incompatible with centralized authentication systems.
New York’s bill adds another layer to the screening requirement. It includes an in-person sales requirement, meaning all 3D printer purchases must occur face-to-face. No online sales. No mail order. For makers and small manufacturers who rely on specialized equipment available only through direct-from-manufacturer channels, this represents a significant market constraint.
The proposals focus on the machinery itself, rather than solely on unlawful manufacture. That shift has consequences for how fabrication tools are designed and sold.
The Real Consequences: STEM, Small Business, and Open Source
Adafruit also outlined how the technical mandates could cause ripple effects nationwide.
In education, compliance tied to proprietary software or cloud verification could mean recurring licensing costs and forced upgrades. If printers must check files against an external server before printing, teachers and students may lose the ability to modify designs freely, test variations, or run projects offline.
For small manufacturers, the economics are punishing. Compliance costs favor larger vendors with legal departments. New York’s penalties enable civil fines of up to $5,000 for a first offense and $10,000 for subsequent violations, creating liability tied to the sale of non-compliant equipment. Smaller operations and open-source developers would struggle to compete.
The innovation ecosystem faces similar pressures. Adafruit argues file authentication could extend to material controls, leading to proprietary consumables and closed systems, pushing the industry toward more waste rather than less.
Washington State Representative Jim Walsh has warned the language is “overbroad” and could sweep makers of lawful products into legal scrutiny. Adding to that, national advocacy voices cited by Adafruit described the Washington bill as setting “a dangerous precedent for the enforcement and policing of the internet.”
Addressing this, Adafruit has proposed alternatives: narrow enforcement to intentional illegal manufacture, replace file scanning with point-of-sale warnings, exempt open-source firmware, establish seller safe harbor provisions, and require independent feasibility assessments.
New York’s bill establishes a 90-day working group to define compliance standards. Adafruit argues the group’s composition will determine whether standards accommodate open-source development or default to proprietary vendor solutions.
“If you don’t have any open-source repos,” the company suggests, “maybe you shouldn’t be setting the rules for open-source tools.”
Although both proposals are still in relatively early stages, the legislative clock is already ticking. New York’s working group has yet to convene, and Washington’s bill remains in committee, leaving room for amendments but not indefinitely.
Adafruit is working to ensure the maker community is represented in those discussions. How these two states resolve the tension between public safety and open manufacturing could set the template for similar legislation nationwide.
The 3D Printing Industry Awards are back. Make your nominations now.
Do you operate a 3D printing start-up? Reach readers, potential investors, and customers with the 3D Printing Industry Start-up of Year competition.
To stay up to date with the latest 3D printing news, don’t forget to subscribe to the 3D Printing Industry newsletter or follow us on LinkedIn.
While you’re here, why not subscribe to our Youtube channel? Featuring discussion, debriefs, video shorts, and webinar replays.
Featured image shows STL Preview of the Urutau. Image via the Global Network on Extremism & Technology.
