The Supreme Court has closed a loophole that enabled “ghost guns”, guns manufactured using kits and 3D printers, to not be tracked by law enforcement. After winding its way through appeals, the Justices voted 7-2 in favor of regulating ghost guns under the Bureau of Bureau of Alcohol, Tobacco, Firearms and Explosives.
Ghost guns, also known as privately made firearms, lack serial numbers that would allow law enforcement to trace their origin to a buyer, and background checks have not been required to build them. Ghost guns have proven something of an intractable problem for law enforcement as 3D printers have become widely available, with tinkerers and libertarian groups offering CAD designs online for anyone to use.
Pieces of the weapon Luigi Mangione used in the slaying of United Healthcare CEO Brian Thompson are believed to have been 3D printed.
The rise of 3D printers created a burgeoning economy of tinkerers who design receivers, which has traditionally constituted the actual “firearm” component, that anyone can then print. Some companies will sell enthusiasts legal parts—including the firing mechanism and and aluminum spine—alongside a milling tool to produce the receiver. Language introduced during the Biden administration sought to clamp down on this by updating the definition of the “Frame or Receiver” to explicitly include kits capable of being converted into functioning firearms as being regulated like a firearm.
In recent years law enforcement agencies across the United States have seen a surge in sales of ghost guns— the Supreme Court cited an increase of 1,600 in 2017 to more than 19,000 in 2021.
Defendants, and the dissenting Justices, sought to challenge the government’s authority to regulate any weapons parts kits and unfinished frames or receivers, citing statues saying that the Gun Control Act of 1968 only grants authority over any weapon “designed to or may readily be converted expel a projectile by the action of an explosive.” A lower court Fifth Circuit Court ruling determined that no weapons parts kit can ever satisfy the requirements. However, the Supreme Court disagreed:
To appreciate why, it helps to work with an example. Take a weapon parts kit featured prominently in the record before us: Polymer80’s “Buy Build Shoot” kit. It comes with “all of the necessary components to build” a Glock-variant semiautomatic pistol. And it is so easy to assemble that, in an ATF test, an individual who had never before encountered the kit was able to produce a gun from it in 21 minutes using only “common” tools and instructions found in publicly available YouTube videos
The dissent argued on other technical matters, including that a weapons parts kit cannot be considered a “weapon” without a fully functional frame or receiver, and that “no such kit” includes those parts. Again, the majority determined that the GCA does not specify a weapon must have those parts, but that the law covers anything that can quickly be prepared for live fire.
Now that the ruling has been made, companies selling frames or receivers and kits for building firearms will need to create serial numbers and conduct federal background checks on their customers. Unless President Trump decides to eliminate the ATF by executive decree.
Anyone can still theoretically make weapons from free blueprints themselves. The ruling pertains to selling and distribution.
You can read the Supreme Court’s opinion here.
