With the stroke of Governor Tina Kotek’s pen, the specter of a criminal prosecution now hangs over owners of homemade guns in Oregon.

The Democrat signed House Bill 2005 into law late last week. The bill prohibits the manufacture, possession, and sale of any unserialized firearm or unfinished frame and receiver. It also bans manufacturing, possessing, and selling “undetectable firearms,” defined as a 3D-printed gun made “entirely of nonmetal substances.”

The ban on so-called ghost guns, which have increasingly become a target for activists in recent years, comes shortly after President Joe Biden’s attempt to do the same through ATF rulemaking was tossed by a federal appeals court. Still, the bill’s signing notches another win for gun-control advocates in the Beaver State. It becomes law the same week an Oregon federal judge upheld the state’s ballot-initiated permit-to-purchase requirement and ban on magazines capable of holding more than ten rounds. That continued success could create momentum for the state’s Democrat-controlled legislature to pursue even more restrictive measures in future sessions.

Supporters of the bill celebrated its passage as part of a broader effort.

“After years of work, my colleagues and I took action on ghost guns with House Bill 2005,” Oregon Senator James Manning (D.), the bill’s chief sponsor, said. “Ghost guns are unserialized and undetectable, making them the gun of choice for gun traffickers, violent criminals, and people legally prohibited from buying firearms.”

Opponents of the measure disagreed that the bill was targeted toward criminals.

“Prohibited persons, such as felons, are already prohibited by existing law from possessing any firearms, whether home-built or mass produced,” the NRA’s Institute for Legislative Action said in an alert on the bill signing. “This new law only harasses hobbyists and will not improve public safety.”

The Oregon Firearms Federation (OFF) called the bill “clownish” and “inane.”

“We have received a number of inquiries about what this bill actually does,” the group said in a statement to its supporters. “But the bill is so poorly drafted that we can’t really answer that question with any certainty.”

OFF, which has been involved in numerous lawsuits against the state’s gun control laws, told its members that it would not be filing suit against HB 2005. Instead, it noted that the Oregon House Republicans pledged to file a lawsuit against the ban.

Kotek’s office did not respond to a request for comment. Neither did the Oregon House Republican Caucus.

Republicans in the Oregon legislature fought to derail the bill during the legislative session but could not stop it due to being in the minority in both chambers. However, they successfully secured certain concessions from the Democratic majority on some additional gun control proposals attached to HB 2005.

The original bill would have created new exceptions to the state’s firearms preemption law to allow cities and counties to create their own gun-free zones. It would have also raised the minimum age to purchase any firearm in the state from 18 to 21. Those provisions were stripped from the bill as part of a deal to bring Senate Republicans, who had staged a multi-week walkout to prevent a legislative quorum from being reached in protest of the bill, back to the chamber to continue working in the legislature.

House Bill 2005 took effect immediately upon Kotek’s signature, though it will not be enforced until September 1, 2024. Current owners of any unserialized guns or gun parts have until then to get a unique serial number from a Federal Firearms Licensee (FFL). After September of next year, selling or possessing an unserialized frame, receiver, or firearm will be a “Class B violation” punishable by a fine for first offenses. The manufacture or sale of an “undetectable” 3D-printed firearm will be a felony, while possession will be a misdemeanor.

The bill makes Oregon the thirteenth state to outright ban or significantly restrict unserialized homemade firearms and the second state to enact such a ban this year after Colorado.