The Supreme Court on March 26 upheld a Biden administration rule targeting the proliferation of unserialized, untraceable “ghost guns,” allowing federal authorities to regulate the sale of kits and parts used to assemble the weapons.
The 7-2 decision in Bondi v. VanDerStok allows the Bureau of Alcohol, Tobacco, Firearms and Explosives to enforce a 2022 regulation aimed at addressing what law enforcement has described as a growing public safety crisis.
Justice Neil Gorsuch authored the 24-page majority opinion, joined by the court’s liberal bloc and three other conservative justices: John Roberts, Brett Kavanaugh, and Amy Coney Barrett. Gorsuch wrote that federal law allows the ATF to regulate not only fully functioning firearms but also weapons that are designed to function like guns or can be easily converted into them.
Justices Clarence Thomas and Samuel Alito dissented, arguing that the ATF had exceeded its authority.
As gun kits became more widely available in the past decade, the annual number of ghost guns recovered by law enforcement and submitted to the ATF for tracing surged from roughly 1,600 in 2017 to more than 27,000 in 2023, the latest figure available. Police departments across the United States have “confronted an explosion of crimes” involving ghost guns, Gorsuch’s majority opinion noted. Lacking serial numbers, these guns are exceedingly difficult for law enforcement to trace.
The ATF rule, which took effect in August 2022, expanded the legal definition of “firearm” to include weapons kits and partially completed frames and receivers — the core components of a gun — that “can readily be converted” into working firearms. Consequently, those kits became subject to the same regulations as standard guns, including requirements for serial numbers and background checks for purchasers.
The decision comes as a blow to gun rights groups and manufacturers of ghost gun kits. The court specifically singled out Polymer80’s “Buy Build Shoot” kit, which comes with “all of the necessary components to build” a semiautomatic pistol similar to a Glock.
“Of course, as sold, the kit requires some assembly,” Gorsuch wrote for the majority. “But a number of considerations persuade us that, even as sold, the ‘Buy Build Shoot’ kit qualifies as a ‘weapon.’”
Polymer80 had been the largest manufacturer of ghost gun kits, but in 2024, The Trace reported that the company had effectively shuttered after facing lawsuits and a market largely scuttled by the ATF rule.
The decision is the latest in a string of divergent Supreme Court rulings on guns. The justices expanded gun rights in a landmark 2022 decision in New York State Rifle & Pistol Association v. Bruen. Last year, the court struck down a federal ban on rapid-fire bump stocks in Garland v. Cargill, then upheld a gun ban for alleged domestic abusers in United States v. Rahimi.
While the Supreme Court’s ghost gun decision puts to bed many of the questions surrounding the legality of the ATF rule, the Trump administration could still choose to rescind it. In February, President Donald Trump ordered the Justice Department to review the Biden administration’s gun reforms, including the ghost gun rule, for any “ongoing infringements” of people’s gun rights.
“The fact that it’s a permissible regulation under the statute does not mean it’s required,” said Andrew Willinger, the executive director of the Duke University Firearms Law Center. “The Trump administration could say, ‘We think this is bad policy. And we’re going to start the process of repealing the rule.’”
Kris Brown, president of the gun reform group Brady, said she hopes the ruling will deter the administration from reversing the rule because doing so “would absolutely invite litigation.”
“President Trump always talks about his tough-on-crime agenda,” she said. “If you really care about making Americans safe, these are the right combination of laws to do that, and the Supreme Court basically recognized that principle today, including justices that this president hand-selected.”
The case’s main plaintiff, the Firearms Policy Coalition, has been a major player in a multimillion-dollar legal campaign to dismantle gun laws through the Supreme Court’s conservative majority. The case highlights the role of dark money in legal battles over gun regulation. As The Trace previously reported, a group established by Dale Sutherland, a former police officer who once worked to get firearms off the streets of Washington, D.C., funneled millions of dollars in anonymous dark money to an FPC affiliate and the law firm that drove the case to the Supreme Court.
The FPC posted on X, “We are disappointed with the Supreme Court’s misguided decision but recognize this is only one battle in a multi-generational war over the scope of government and pre-existing right to keep and bear arms.” The group said it will “continue communicating with the White House, the Attorney General, and the Department of Justice to encourage a full repeal of the ATF’s rule.”
Ghost guns have been used in several high-profile shootings in recent years, most recently the December killing of United Healthcare executive Brian Thompson in midtown Manhattan. A 2023 mass shooting involving an AR-15-style ghost gun left five people dead in Philadelphia. In Santa Clarita, California, in 2019, a 16-year-old high school student armed with a ghost gun killed two classmates and wounded three others.
As the case came before the Supreme Court, a group of 20 major cities urged the justices to uphold the rule change, saying it had curbed ghost gun-related crime. In Baltimore, for example, police recovered 26 percent fewer ghost guns in 2023 than in the previous year — the first drop since 2019.
The Supreme Court explicitly raised the possibility of future challenges. Gorsuch’s opinion said the rule may not cover every weapons kit on the market. “That leaves the door open to there being situations where something is so far from an operable firearm that it doesn’t come within the definition,” Willinger said.
Gun violence prevention groups called the decision a sweeping victory for gun safety.
“We are thrilled that the Supreme Court has upheld the ATF rule that treats ghost guns as what they are: guns,” said David Pucino, the legal director and deputy chief counsel at Giffords Law Center, a gun reform organization. “We’ve seen how the rise in ghost guns has contributed to increases in crime and gun deaths in communities across the United States.”
