MADISON, Wis. – The Wisconsin Department of Justice (DOJ) joined a group of 20 states in filing a friend of the court brief supporting the federal government’s efforts to regulate “ghost guns”: unserialized, untraceable weapons that are often made at home and purchased without background checks.

The new federal rule to regulate ghost guns—issued by the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF)—will require that buyers pass background checks before purchasing weapons parts kits, and that law enforcement officers can trace self-made guns that are later used in a crime.

“This federal rule closes a loophole and ensures that the rules for ghost guns are the same as those for other firearms,” said Attorney General Josh Kaul. “Common-sense gun-safety measures like this can help prevent gun violence and make our communities safer.”

Absent federal enforcement, these dangerous weapons have continued to proliferate, including in states that have tried to regulate ghost guns themselves. The ATF’s Final Rule helps curb this problem by serving as a vital backstop to existing state efforts to stem the flow of ghost guns.

The ATF’s Final Rule regulates ghost guns by clarifying critical definitions in the Gun Control Act. Specifically, the Final Rule makes it clear that weapon parts kits and partially complete frames or receivers—the key building blocks for ghost guns—are “firearms” under the Act if they can be readily converted to function as a firearm. In making this sensible clarification, the Final Rule helps ensure that these kits and partially complete frames or receivers are subject to the same serialization and background check requirements as conventionally manufactured guns. This helps close a dangerous loophole in firearms regulation that has enabled people to evade existing gun laws and get their hands on these dangerous weapons.

A copy of the brief is available here.

DOJ is joined by the following states in filing the amicus brief, California, Colorado, Connecticut, Delaware, District of Columbia, Hawaii, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Jersey, New York, North Carolina, Oregon, Pennsylvania, Rhode Island, and Washington.