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MEMO: The Dangers of Ghost Guns


TO Interested Parties FROM Giffords Law Center to Prevent Gun Violence DATE November 22, 2019 RE The Dangers of Ghost Guns __________

Last week’s  shooting at Saugus High School  in Santa Clarita, CA highlighted a dangerous trend: the increasingly frequent use of “ghost guns,” firearms manufactured in the home which can be obtained without a background check, lack serial numbers, and are therefore untraceable by law enforcement if used in a crime. Ghost guns, sometimes referred to as “do-it-yourself guns,” are assembled by unlicensed persons, rather than licensed manufacturers, and generally evade all the regulations which apply to the regulated firearms industry.

Ghost guns can be easily produced from kits, widely available online with no background check. These kits include a key firearm component called a receiver or frame, which contains the firing mechanism of the gun. (“Receivers” are the foundation of rifles like AR-15 assault weapons, while “frames” are the foundation of pistols like the handgun used in the Santa Clarita shooting.) Sellers of the kits used to build ghost guns deliberately leave the receivers or frames they sell unfinished in order to avoid falling under the jurisdiction of federal and state gun laws which apply to fully finished frames and receivers.

The critical danger posed by ghost guns results from the fact that unfinished—or “80%”—receivers or frames can be completed with minimal skill in as little as 15 minutes and then combined with other readily available components to produce a fully functional yet untraceable firearm.

 Ghost guns have already been used in mass shootings  by shooters who would have been unable to purchase a typical serialized gun, either because the gun itself was illegal in that state or because  the shooters were prohibited from purchasing guns  and unable to pass a background check. Criminal enterprises are  increasingly  exploiting these technologies and ghost guns now represent  30% of all crime guns recovered in California .

 ***Giffords Experts are Available for Comment on this Trend***   

  • Adam Skaggs, Giffords Law Center Chief Counsel
  • David Pucino, Giffords Law Center Staff Attorney
  • David Chipman, Giffords Senior Policy Advisor & Former ATF Special Agent

Exploiting Loopholes

When American gun laws were written, legislators assumed that firearms would either be imported from abroad by dealers or manufactured domestically by professional gun manufacturers. Ghost guns exploit the loopholes behind these assumptions: ghost gun kits are carefully and intentionally designed to come as close to providing the end user with a firearm as possible without actually meeting the legal definition of “firearm.”

As a result, more and more people are able to easily craft their own firearms at home. In February 2019, for example, a man who was prohibited from possessing a firearm was  sentenced to prison  after police officers caught him with an AR-15-style rifle built using a 3D-printed receiver. The man could not purchase firearms through a licensed dealer because of his history of domestic violence, so he built his own using a 3D-printer. The man was arrested by police officers who heard him firing the gun. In addition to the untraceable AR-15, the man was carrying what prosecutors called a hit list labeled “9/11/2001 list of American Terrorists,” which included the names and addresses of federal lawmakers.

In 2017, a man who was prohibited from owning a gun and under prosecution for multiple crimes killed six people and injured 10 in Rancho Tehama Reserve, California with two assault-style rifles he assembled using parts ordered online. At least one unregistered semi-automatic ghost rifle and two borrowed semi-automatic pistols were used.

Undermining State Laws and Law Enforcement

When law enforcement agencies recover firearms that have been used in crimes, the agencies can usually trace the firearms to their first retail purchaser and use that information to investigate and solve the crime. Tracing depends on the ability to identify firearms based on their serial number: traditionally, when a firearm is manufactured domestically or imported from abroad, it is engraved with a serial number and markings that identify the manufacturer or importer, make, model, and caliber, and are unique to the firearm. Using this information, the Bureau of Alcohol, Tobacco, Firearms & Explosives (ATF) can track firearms from the manufacturer or importer through the distribution chain to the first retail purchaser. ATF works extensively with other law enforcement agencies to trace firearms using this technique— in 2017 alone, ATF conducted 408,000 traces . Federal law only requires licensed manufacturers and importers to serialize their guns. Ghost guns escape this federal serialization requirement, undermining law enforcement tracing efforts.

These partially finished components also escape the federal background check requirement that applies to the retail sale of firearms. As a result, individuals who wouldn’t be able to buy a firearm, whether that is because of a felony record, a history of domestic abuse, or even the fact that they are underage, could simply buy a ghost gun kit and make a gun themselves, with no background check and no questions asked.

 California  and  Connecticut  have enacted laws that couple a serialization requirement with a registration requirement: individuals who manufacture or assemble a ghost gun must request a unique serial number from state law enforcement agencies and engrave that serial number on the firearm. If one of these firearms is subsequently recovered by a law enforcement agency, it will be possible to identify and trace the firearm using law enforcement records records.  New Jersey  has gone a step further, banning unserialized frames and receivers altogether. These developments are helpful, but because ghost guns can flow freely across state lines, only a comprehensive national serialization law can fully address the problem.

Federal Solutions

The ease of access to untraceable, unserialized firearms should be addressed by closing the loopholes which allow ghost guns to escape regulation as firearms. This could be accomplished by expanding the federal definition of “firearm” to include not just finished receivers but unfinished receivers as well. This more expansive definition would have the effect of requiring people in the business of manufacturing these receivers to serialize them. It would also require people in the business of selling these receivers to conduct background checks on purchasers.

Online posting of the code for 3D printing firearms should also be explicitly illegal, as should be the distribution to the unlicensed public of machines like the  Ghost Gunner that were specifically created for the manufacture of guns. Firearms produced using 3D printing should be treated the same as firearms produced using traditional methods: one should have to obtain a license in order to manufacture or sell 3D-printed guns, those guns should have to be serialized, and transfers should be permissible only after a background check, if their transfer is permitted at all.

In July 2019, the House of Representatives adopted an  amendment  sponsored by Rep. Norma Torres (D-CA) to the National Defense Authorization Act for Fiscal Year 2020 (NDAA) which would prevent the president from moving weapons export licensing from the USML, the list at issue in the Defense Distributed litigation, to the Commerce Department’s Commerce Control List (CCL). Because posting 3D-printed gun code online constitutes an export of technical data, which is currently prohibited by the State Department, posting blueprints will continue to be prohibited so long as weapons export licensing remains on the USML.

Additionally, several bills have been introduced in the 116th Congress to address ghost guns and 3D-printed guns. In June, Representative David Cicilline (D-RI) introduced the  Untraceable Firearms Act , which would prohibit the manufacture and sale of firearms without serial numbers. Senator Ed Markey (D-MA) and Representative Ted Deutch (D-FL) introduced the  3D Printing Safety Act  to prohibit the online publication of computer-aided design (CAD) files which automatically program a 3D-printer to produce or complete a firearm.


By leveraging new technology, individuals who promote and make ghost guns are exploiting gaps in the laws regulating firearms. These firearms can avoid detection through existing security systems, they are accessible to individuals who would otherwise be unable to obtain them, and they are untraceable. As 3D-printing technology develops and machines that use more robust materials become cheaper, the quantity and quality of 3D-printed guns is likely to increase and improve, exacerbating each of these dangers. In addition, ghost guns assembled from unfinished components are increasingly produced not just by lone individuals, but as part of criminal enterprises. Congress should pass legislation to prevent criminals and dangerous people from circumventing firearms regulations and prevent the proliferation of untraceable, unserialized firearms and firearm parts.