by Emily Pecot
The legal landscape of gun safety faces a new frontier centering around the “ghost gun.” While the term ghost gun may be catchy, the official name is “privately made firearms” (PMFs), and these untraceable weapons present a significant challenge for courts and law enforcement.
PMFs are firearms that people build themselves, often from kits bought online. The key component in a ghost gun kit is called an “80% receiver” or frame, which is deliberately left unfinished. The “80%” refers to the amount of work already completed when someone purchases the kit.
Under the Gun Control Act of 1968, the “incompleteness” of the receiver means it is not legally considered a firearm. This loophole allows people to buy ghost gun kits without background checks, or other gun safety regulations that are applied to traditional guns. Once assembled, the ghost gun works just like any other firearm, but without a way to track who owns it or where it came from. The weapons are untraceable because they lack serial numbers, which are similar to a product’s bar code or a car’s VIN number.
PMFs can also be made using 3D printers, presenting an even more difficult challenge for regulators. People can download digital blueprints and print parts at home, making the manufacturing process even more decentralized.
Andrew Willinger, a professor at Duke University Law School and executive director of the Duke Center for Firearms Law, notes, “If gun assembly kits are not considered firearms, then they can be sold without the seller conducting a background check on the purchaser to determine whether that person is prohibited from possessing a gun.”
For example, convicted felons and domestic abusers with restraining orders against them are prohibited from possessing guns and therefore would not pass a background check. However, through the internet, they can purchase a ghost gun kit.
The untraceable nature of ghost guns has a significant impact on criminal investigations. According to statistics from the U.S. Department of Justice, between 2016 and 2020, nearly 45,000 “privately made firearms,” or ghost guns, were recovered from crime scenes or during criminal investigations. According to the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF), 99% of those guns can’t be traced. ATF data from 2017 to 2023 shows law enforcement recovered 92,702 PMFs.
Stats prompt action
In 2021, soon after taking office, President Joseph Biden directed the ATF and the Justice Department to regulate ghost guns. In April 2022, ATF issued a new rule surrounding ghost guns. The rule stated that ghost gun kits would be considered as a firearm under the Gun Control Act of 1968. That meant that, like any other firearm, ghost guns would require serial numbers, and those purchasing them would be subject to a background check.
“This allows us, ATF, to track these firearms when we’re covering a crime scene and give that information back to a police department so they can have a lead or someplace to start an investigation involving a crime with that firearm,” Special Agent in Charge David Booth with ATF’s Denver Division told CBS News when the rule was announced. “In this state, if you sell a firearm, you’re required to go through a dealer. So, if you make a (privately made firearm) and you want to sell it to me, you have to take it to a dealer now and the dealer has to mark it and conduct a background check on me.”
Agent Booth said that because the gun is now marked if it is involved in a crime or if it gets stolen, the police have the means to trace it.
According to statistics from Everytown, a non-profit organization that advocates against gun violence, the ATF rule change led to a reduction in the number of ghost guns recovered at crime scenes. For example, 2024 crime statistics from the Los Angeles Police Department revealed that the recovery rate of ghost guns at crime scenes in LA dropped by 50% since 2022. Several other major cities like Philadelphia, New York and Baltimore also saw a decline in ghost gun recoveries in 2023, offering evidence that the rule had an impact.
U.S. Supreme Court weighs in
Two individual gun owners, along with a gun-rights advocacy group, challenged the new rule in a Texas federal court. The case—Bondi v. VanDerStock, formerly Garland v. VanDerStock, eventually ended up at the U.S. Supreme Court. The case’s name change occurred because there was a change in presidential leadership and in the U.S. Attorney General. The Court heard oral arguments in the case in October 2024 when it was still called Garland v. VanDerStock. The case’s name changed to “Bondi,” the newly appointed U.S. Attorney General, after President Donald Trump took office in January 2025.
According to Professor Willinger, the case was really a question of administrative law and not a true Second Amendment case.
“The argument was that ATF had exceeded its authority as a federal agency to interpret the language that Congress enacted back in 1968,” Professor Willinger says.
In other words, had the ATF acted in an arbitrary way when it wrote the new rule because it didn’t actually have the statutory authority to say that a gun assembly kit should be classified as a firearm under the Gun Control Act of 1968.
In March 2025, the majority of the Court in a 7-2 decision upheld the Biden-era federal rule, finding that the Gun Control Act’s wording allowed the ATF to regulate ghost gun kits.
In the majority opinion for the Court, Justice Neil Gorsuch compared gun kits to an unfinished manuscript or a piece of furniture that needs to be assembled. He also called out one kit in particular—Polymer80’s kit which is called “Buy Build Shoot.”
“An author might invite your opinion on her latest novel, even if she sends you an unfinished manuscript. A friend might speak of the table he just bought at IKEA, even though hours of assembly remain ahead of him,” Justice Gorsuch wrote. “In the same way and for the same reason, an ordinary speaker might well describe the ‘Buy Build Shoot’ kit as a ‘weapon.’ Yes, perhaps a half hour of work is required before anyone can fire a shot. But even as sold, the kit comes with all necessary components, and its intended function as [an] instrument of combat is obvious. Really, the kit’s name says it all: ‘Buy Build Shoot.’”
The dissenting justices disagreed with the majority, believing ATF had overstepped its authority and that only Congress can regulate firearms parts, which it has not done.
“The Government asked this Court just last Term to ‘rewrite’ statutory text so that it could regulate semiautomatic weapons as machine guns. We declined to do so,” Justice Clarence Thomas wrote in his dissent, referring to a decision that struck down the rule classifying bump stocks as machine guns. “The Government now asks us to rewrite statutory text so that it can regulate weapon-parts kits. This time, the Court obliges.”
A patchwork of laws
While the U.S. Supreme Court has weighed in on the federal rule, Professor Willinger anticipates more state-level cases. In the absence of fully settled federal law, many states have taken matters into their own hands, creating a complex and varied set of laws across the country. These state-level rules often go further than the federal standard.
State laws on ghost guns in New Jersey, for example, require serial numbers and background checks for component parts, require all ghost guns to be reported to officials, ban the 3D printing of guns, as well as the distribution of 3D printing instructions, and also ban plastic undetectable guns.
“We’re going to see a lot of this action happening at the state level,” says Professor Willinger. “We could end up with a situation where these devices are treated differently in different states.”
Discussion Questions
- Do you agree or disagree with the U.S. Supreme Court’s ruling in Bondi v. VanDerStock? Explain your answer.
- Do you think Congress should regulate PMFs or ghost guns like any other firearm? Why or why not?
Glossary Words
felon— a person that is convicted of a felony, which is a crime usually punished by imprisonment of more than one year.
majority opinion—a statement written by a judge or justice that reflects the opinion reached by the majority of their colleagues.
statutory—based on legislative enactment.
upheld—supported; kept the same.
This article originally appeared in the Fall 2025 issue of The Legal Eagle