In the United States, traditional firearms manufacturers are licensed, and firearms are sold through licensed gun dealers.  These weapons also must bear serial numbers on the back of their frames to assist law enforcement with tracing guns used in crimes.ⁱ  “Ghost guns,” also known as privately made firearms (PMF’s), are prepackaged firearm parts and equipment that can be bought online in the form of DIY kits.  Once assembled, they constitute and operate as firearms.ⁱⁱ  These kits generally include an unfinished frame or receiver which is the piece of the firearm containing the operating parts of the firing mechanism of a weapon.  To avoid definition as a firearm under current laws, these unfinished frames are no more than 80% complete at sale.   Once assembled, however, that are regulated under federal and some state laws.  Ghost gun kits, some AR-15 kits costing only $345,ⁱⁱⁱ  contain all the component parts needed to turn the unfinished frame into a handgun or assault weapon, usually including the proper drill bits used with the only tool needed for assembly.  Numerous YouTube videos and internet sites exist to guide ghost gun purchasers in how to assemble these parts at home.^iv  But because gun regulation loopholes do not recognize these unassembled kits as firearms, their sale is often totally unregulated and the kits can be purchased by anyone, even persons who could not pass background checks under existing laws.  Because they are bought in parts as kits, they also are not serialized, thus are untraceable.^v 

On August 18, 2021, in a new approach to decrease gun violence, San Francisco District Attorney Chesa Boudin announced that his office had filed a civil prosecution case against three corporations that manufacture and distribute ghost gun kits in California.^vi   According to DA Boudin, the lawsuit is a challenge to those responsible for bringing unregulated and dangerous weapons into the city and state.  “Ghost guns pose a grave threat to public safety; these untraceable firearms are readily available to children and prohibited persons,” stated Boudin.  Boudin’s office is partnering with private attorneys and leading firearm litigation and regulation experts in its litigation of this matter.^vii

The ghost guns suit arises from DA Boudin’s invoking his civil powers under California law—a power to civilly prosecute corporations for violations of law.  The suit seeks monetary penalties and injunctive relief that would prohibit the defendants from violating state and federal laws.  According to the suit, the defendants’ legal violations include noncompliance with the California Unfair Competition Law, various code sections of the Business and Professions Code and the California False Advertising Law.^viii   The complaint further alleges violations of the federal Gun Control Act and California gun control laws, along with the California Unsafe Handguns Act which requires certain firearms to meet safety testing standards.^ix 

San Francisco recently reported a substantial jump in the number of shootings in the City, a 181% increase over 2020.^x  Police there also report confiscating more and more ghost guns, an increase from only 6 in 2016 to 164 in 2020.^xi   According to the San Francisco Police Chief, nearly ½ of the guns seized by his department and associated with homicide in the City in 2020 were ghost guns, a significant increase since 2019 when that number was only 6%.^xii  According to the City’s police department, as of August of 2021, its crime lab has already processed over 150 ghost guns.^xiii   Law enforcement authorities argue that ghost guns impede investigations of firearm crime. The fact that the guns lack serial numbers and that there are no records of their sale means that law enforcement cannot successfully trace them through ATF databases or the California Department of Justice records when they are recovered in crime investigations.^xiv