WASHINGTON (AP) — The Supreme Court on Wednesday upheld a Biden administration regulation on the nearly impossible-to-trace weapons called ghost guns, clearing the way for continued serial numbers, background checks and age verification requirements for buying the kits online.

The 7-2 opinion found that existing gun laws allow regulation of the kits increasingly linked to crime. It comes after President Donald Trump ordered a review of federal gun policy that could undermine or reverse regulations championed by his predecessor.

Sales of the homemade firearms grew exponentially as kits allowing for easy at-home building came into the market, Justice Neil Gorsuch wrote in the majority opinion. “Some home hobbyists enjoy assembling them. But criminals also find them attractive,” he said.

The number of ghost guns found at crime scenes around the country has also soared, according to federal data. Fewer than 1,700 were recovered by law enforcement in 2017, but that number grew to 27,000 in 2023, according to Justice Department data.

Since the federal rule was finalized, though, ghost gun numbers have flattened out or declined in several major cities, including New York, Los Angeles, Philadelphia and Baltimore, according to court documents. Manufacturing of miscellaneous gun parts also dropped 36% overall, the Justice Department has said.

Ghost guns are any privately made firearms without the serial numbers that allow police to trace weapons used in crime. The 2022 regulation was focused on kits sold online with everything needed to build a functioning firearm — sometimes in less than 30 minutes, according to court documents.

Ghost guns have been used in high-profile crimes, including a mass shooting carried out with an AR-15-style ghost gun in Philadelphia that left five people dead. Police believe a ghost gun used in the slaying of UnitedHealthcare's CEO in Manhattan was made on a 3D printer rather than assembled from a kit of the kind at the center of the Supreme Court case.

Finalized at the direction of then-President Joe Biden, the "frame and receiver" rule requires companies to treat the kits like other firearms by adding serial numbers, running background checks and verifying that buyers are 21 or older.

Gun groups challenged the rule in court in the case known as Garland v. VanDerStok. Most crimes are committed with traditional firearms, not ghost guns, they argued. It's legal for people to build their own firearms at home, the challengers said, arguing that the Bureau of Alcohol, Tobacco, Firearms and Explosives overstepped its authority by trying to regulate the kits.

The Supreme Court majority disagreed, pointing out that the law gives the ATF the power to regulate items that can be quickly made into working firearms.

“The ‘Buy Build Shoot’ kit can be 'readily converted' into a firearm too, for it requires no more time, effort, expertise, or specialized tools to complete,” Gorsuch wrote, referring to a specific product.

Some kits may take more time to build into guns and therefore fall outside the ATF’s power, he wrote, but many popular kits are subject to regulation.

In response to the ruling, a Justice Department spokesperson said the administration would “continue to support and defend the Second Amendment rights of all Americans.”

Gun safety groups celebrated the ruling, with Everytown Law executive director Eric Tirschwell saying the rule also had broad support from law enforcement. “Fundamentally, today's decision confirms the ghost gun industry is dead as a viable business model," he said.

A Michigan woman whose son lost an eye when he was accidently shot by a friend who bought a ghost gun before he was old enough to legally buy a typical weapon also applauded. “We are deeply relieved by today’s ruling, which will help ensure that a tragedy like ours never happens again,” she said.

New Jersey Attorney General Matt Platkin said the ATF policy is a major factor in two years of record-low numbers of shootings in his state. “These are common-sense regulations on ghost guns that all too often end up in the hands of felons,” he said.

The court previously expanded Second Amendment rights with a finding that modern gun regulations must fit within historical traditions. The justices also struck down a firearm regulation from President Donald Trump's first administration, a ban on gun accessories known as bump stocks that enable rapid fire.

In a dissent, Justice Clarence Thomas wrote that the ghost gun rule should meet the same fate. The kits, he wrote, are only firearm parts and shouldn't be subject to a regulation that could open the door to rules on other popular weapons. “Congress could have authorized ATF to regulate any part of a firearm or any object readily convertible into one," he wrote. “But, it did not.”

Justice Samuel Alito also filed his own dissent.

___

Associated Press writer Darlene Superville in Washington and Geoff Mulvihill in Cherry Hill, New Jersey, contributed to this report.

___

Follow the AP's coverage of the U.S. Supreme Court at https://apnews.com/hub/us-supreme-court.

FILE - The Supreme Court at sunset in Washington, Feb. 13, 2016. (AP Photo/Jon Elswick, File)

Credit: AP

icon to expand image

Credit: AP

FILE - The Supreme Court in Washington, June 30, 2024. (AP Photo/Susan Walsh, File)

Credit: AP

icon to expand image

Credit: AP

Featured

Georgia Power's Plant Bowen in Cartersville is shown in this 2015 photo. (Hyosub Shin/Atlanta Journal-Constitution/TNS)

Credit: hshin@ajc.com