‘Ghost Guns’: What They Are and Why There Has Been a Fight Over Them

The Supreme Court on Wednesday upheld federal restrictions the Biden administration placed on “ghost guns,” drawing a spotlight to the kits that can be assembled into homemade firearms and the new front in the fight over gun control that they opened up.

Administration officials had said the popularity of the weapons had soared in recent years, particularly among criminals barred from buying ordinary guns. The regulation, issued in 2022 by the Bureau of Alcohol, Tobacco, Firearms and Explosives, broadened the bureau’s interpretation of the definition of “firearm” in the Gun Control Act of 1968.

It did not ban the sale or possession of parts that can be assembled to make homemade guns, but it did require manufacturers and sellers to obtain licenses, mark their products with serial numbers and conduct background checks.

The rule was a centerpiece of President Joseph R. Biden Jr.’s broader initiative to address the proliferation of illegal weapons. Mr. Biden said in 2022 that the rule would “help save lives, reduce crime and get more criminals off the streets.”

But the federal effort to regulate ghost guns has been troubled by uneven enforcement, significant loopholes and court challenges. A federal appeals court had struck down the regulation, but in a 7-to-2 ruling on Wednesday, the Supreme Court said it could remain in place.

Here’s what you need to know about the weapons.

What is a ghost gun?

Traditional firearms are made by licensed companies and then bought from licensed gun dealers. All guns manufactured in the United States, as well as those imported from abroad, are legally required to have serial numbers that are typically displayed on the back of the frame.