Washington — The Supreme Court on Tuesday paused a lower court decision that invalidated the Biden administration's efforts to regulate so-called ghost guns, allowing enforcement of the restrictions while legal proceedings continue.

The 5-4 order from the court came hours before a temporary pause issued by Justice Samuel Alito, who handles requests for emergency relief arising from states including Texas, was set to expire. Chief Justice John Roberts and Justice Amy Coney Barrett joined with the three liberal justices to freeze the lower court's ruling, while Justices Clarence Thomas, Samuel Alito, Neil Gorsuch and Brett Kavanaugh said they would deny the request from the Biden administration to revive the rules. 

The White House commended the Supreme Court's decision to temporarily pause the lower court orders blocking its efforts aimed at curbing gun violence. 

"While this case is being litigated, the Supreme Court's action will keep in place important efforts to combat the surge of unserialized, privately-made 'ghost guns' which have proliferated in crime scenes across the country," Olivia Dalton, White House principal deputy press secretary, said in a statement. 

The legal battle arrived at the Supreme Court late last month when the Biden administration asked the high court to reinstate the Bureau of Alcohol, Tobacco, Firearms and Explosives' regulation targeting ghost guns while proceedings continue in the lower court.

The measure from ATF, which took effect in August 2022, updated the rules regarding the definition of a "firearm" under the Gun Control Act to address the proliferation of ghost guns, which are untraceable firearms that can be made from kits available online and assembled at home. The rule defined "firearm" to include ghost gun kits and clarified the definition of "frames or receivers," which are also sold in kits.

The legal battle over ghost guns

Under the law, manufacturers and sellers of certain kits are required to obtain licenses, mark their products with serial numbers, conduct background checks and maintain records to allow law enforcement to trace the firearms when used in crimes. The rule does not prohibit the purchase, sale or possession of any gun, nor does it bar a person legally allowed to have a firearm from making one at home.

A group of gun owners, advocacy groups and entities that make or sell products covered by the rule challenged portions of ATF's restrictions last year, arguing they're unlawful.

A federal district court first blocked the challenged provisions, prohibiting the Biden administration from enforcing them. Then, on July 5, U.S. District Court Judge Reed O'Connor ruled in favor of the plaintiffs and blocked the regulation nationwide, finding ATF acted beyond the scope of its statutory authority. The Biden administration asked the U.S. Court of Appeals for the 5th Circuit to halt the lower court's decision, and the appeals court declined to do so regarding two challenged portions of ATF's restrictions.

The 5th Circuit expedited the Biden administration's appeal and is set to hear arguments in September.

In addition to asking the Supreme Court to put the district court's order on hold, the Biden administration argued that under a stay, the challengers would be free to make, sell and buy weapons parts kits, and only would need to comply with federal requirements that apply to commercial sales of other firearms.

"The district court's universal vacatur is irreparably harming the public and the government by reopening the floodgates to the tide of untraceable ghost guns flowing into our Nation's communities," Solicitor General Elizabeth Prelogar wrote in the emergency application to the court. "Once those guns are sold, the damage is done: Some will already be in the hands of criminals and other prohibited persons — and when they are inevitably used in crimes, they are untraceable."

But the plaintiffs challenging ATF's rule argued that by redefining "frame or receiver" and "firearm" under federal law, the agency overstepped its authority under the Gun Control Act.

"By seeking to bring within its purview items that facilitate the making of firearms by private citizens for their own use, ATF has sought to fundamentally alter the policy choices made by Congress in 1968," one group of gun owners and retailers told the court. "Those policy choices are for Congress, not ATF, to make."