Facts About Firearm Policy Initiative

Return to Database
MYTH: Universal background checks would not have stopped a single mass shooting


  • Researcher John Lott claims that universal background checks would not have stopped a single mass shooting this century.
  • At least six of the deadliest mass shootings since 2013 could have been prevented with a background check system that closes the loophole that allows the private transfer of firearms.
  • A strong universal background check system that includes a permit-to-purchase requirement could have prevented half of the deadliest US mass shooters from acquiring the firearms used in the attacks.

Lott’s Claim:

The second paragraph of John Lott’s Sept. 18, 2019 testimony before Congress begins with a bold claim that “Universal background checks, meaning background checks on the private transfer of guns, have been mentioned for years by gun control advocates… But there has not been a single mass public shooting this century that such a law would have stopped.”

Later in the testimony, Lott says universal background checks “would not have stopped any of the mass shootings we have seen in this century. And given that drug dealers are a major source of illegal guns, these laws aren’t going to be any more successful in stopping criminals from getting guns than we have been in stopping them from getting illegal drugs.”

The Facts:

Universal background checks would have stopped mass shootings this century. First, it is important to clarify terms. Lott claims that he used the FBI definition of public mass shooting to come to his finding, but this is impossible because the FBI does not have a definition for mass shootings. The FBI does, however, have a definition for an active shooter incident, but Lott’s definition of what constitutes a public mass shooting is at odds with this FBI definition. 

Furthermore, there are multiple definitions for “universal background checks.” The strongest type of universal background checks are permit-to-purchase laws such as the type seen in Massachusetts (which has  one of the lowest gun violence rates in the country). A research report on mass shootings by Nick Wilson released the same month as Lott’s testimony found that “of the 27 deadliest shootings over the last six years where we could identify how the firearms were obtained, a federal licensing requirement may have prevented the shooter from acquiring the firearms used in 52% of the incidents. In these 14 incidents, 169 individuals were fatally shot and 131 individuals were shot and injured.”

Even if Lott is defining universal background checks as a weaker version that only stops the private transfer of guns, plenty of mass shootings have occurred that could have been prevented by closing the private sales loophole.

Eighteen days before Lott made this claim before Congress, a prohibited individual armed with a firearm obtained through a private sale killed seven people and injured 25, including three police officers in the Midland-Odessa area of Texas. The mass shooter attempted to purchase a gun in 2014 but failed a national criminal background check because he had been previously found mentally unfit by a court. On Oct. 8, 2016, the shooter bought an AR-15 style rifle from Marcus Braziel of Lubbock, Texas in a private sale without a background check. Braziel pled guilty in October 2020 to unlicensed firearms dealing and selling guns to at least four individuals prohibited from buying firearms.

A Dallas shooter who targeted police officers in July 2016 also exploited the private sale and gun show loopholes to avoid a background check. In November 2014, the shooter bought an AK-47-style rifle in a private sale in a Target parking lot. The other weapons were believed to be purchased at a gun show or online. The shooter’s history included sexual harassment and violence. He had a protective order filed against him, practiced military drills in the backyard, stockpiled explosives, and received VA treatment for his hallucinations and depression. Police report regularly responding to his panic attacks. 

On August 8, 2015, a man in Texas handcuffed his ex-girlfriend to a bed and forced her to watch him kill her six children and husband before shooting her. The handgun and six pairs of handcuffs were purchased online without a background check through an unlicensed seller within two weeks of the shooting. His lengthy criminal record prohibited him from possessing firearms. He had convictions for aggravated robbery, auto theft, assault, possession of a controlled substance, and DUI. In addition, he was convicted of putting a knife to the throat of his ex-girlfriend, threatening to kill her baby, and retaliation. He received a five year prison term for those crimes. Contrary to Lott’s claim, universal background checks could have prevented this mass shooting by preventing the private sale.

Several mass shooters have been able to buy a firearm from a licensed dealer even though they should not have passed the instant background check. The current background check system has flaws and limitations, most of them a result of federal restrictions encouraged by the gun lobby. For example, the November 2017 Sutherland Springs Church Shooting that claimed the lives of 25 people was perpetrated by a man who obtained the AR-15-style rifle and four other guns from gun stores, despite his disqualifying criminal history from a domestic violence conviction during an Air Force court martial. The shooter’s history included crushing his infant’s skull, threatening to kill himself and his superior officers, threatening his wife with loaded and unloaded guns, physical and sexual assault, threatening to shoot his work place, and animal cruelty. The shooter was denied a permit to carry because of his history, but was still able to obtain multiple guns because the Air Force failed to submit records to the federal background check system. A unified universal background check system would have ensured the disqualifying information was available in the national database.

If a firearm background check is not completed within 3 business days, the gun seller is permitted (but not required) to sell the gun even if the check is not complete. This is called the default proceed rule but is now more commonly known as the Charleston loophole.

The 2015 Charleston AME Church shooter was also able to purchase a firearm despite being legally prohibited. Due to incorrect submission of data and the default proceed rule, the gun seller legally completed the sale before the background check was complete. Before purchasing the firearm, the soon-to-be Charleston AME shooter was arrested twice at a local mall and possessed Suboxone. Then-FBI Director James Comey said Roof’s admission of a narcotics offense should have blocked the purchase of the handgun but “[t]he data was not properly entered in federal criminal justice computer systems.” 

Other mass shooters might have been stopped by a universal background check system that regulates ghost guns and online sales. For example, the 2013 Santa Monica College shooter used an AR-15-type semi-automatic rifle “ghost gun” he purchased online and completed at home. In October 2011, the California Department of Justice told the shooter he was ineligible to purchase a firearm, so he built one using a kit he purchased without a background check online. Similarly, the 2017 Rancho Tehama Reserve perpetrator was out on bail and prohibited by criminal and civil orders from  possessing firearms. Using kits he purchased, the shooter constructed  two semi-automatic AR-15-type rifles which he used to kill five and injure eleven. 


John Lott, “What type of gun control will actually make us safer?” Testimony before the Joint Economic Committee of the United States House of Representatives and the Senate, Senate website, Sept. 18, 2019

Nick Wilson, “Raising the Standard for Gun Ownership: How Firearm Licensing Can Potentially Save Lives,” Guns Down America, Sept. 2019

“Seller of gun used in West Texas mass shooting pleads guilty,” Associated Press, Oct. 7, 2020