Fact check: Have mass shootings decreased in the US since 2022 law?

Senator Chris Murphy, a staunch supporter of stricter gun laws, claimed shortly after the deadly shooting at a Minneapolis school on August 27 that legislation passed during the Biden administration had slowed the number of mass shootings.

According to Murphy, “There is something fundamentally wrong with a nation that makes running for their lives a part of children’s back-to-school customs,”. Mass shooting decreased when we finally passed a gun safety bill in 2022. However, the start was inadvertibly small. More needs to be done.

Following the mass shootings in Buffalo, New York, and a Uvalde, Texas elementary school, Murphy referred to the Bipartisan Safer Communities Act, which was signed into law in June 2022 by then-President Joe Biden. The bill became the first gun control measure passed by Congress in nearly three decades by combining mental health and school security resources with gun safety provisions.

In Minneapolis, Robin Westman shot through the Church of the Annunciation’s windows to start the school year, killing two students and injuring 18 others. Westman, 23, was shot in the head on himself, killing him.

According to Murphy’s spokesman, the senator referenced the number of mass shootings as determined by the Gun Violence Archive, an online database that found a decrease in mass shootings between 2024 and 2023. However, it’s challenging to determine whether the 2022 law caused the decrease. The law may have played a role, according to experts, but they are unaware of any academic research that addresses this issue.

It’s not that this may not have an impact, but it’s important to keep in mind many other potential factors for that drop, such as a drop in crime overall, a return to prevention and intervention strategies, and so on, according to Alex R. Piquero, a former director of the Bureau of Justice Statistics at the University of Miami.

There is no recognized definition of a mass shooting.

No consensus exists regarding a definition of mass shootings. Depending on how many people are injured or killed in a mass shooting, various organizations use various methods to assess the number of victims or victims. Some counts only indiscriminate violence when a shooter fires a gun at random in public, while others list gang violence or domestic violence. Mass shooting numbers can fluctuate significantly depending on the statistics, which range from dozens to hundreds of incidents in a given year.

Mass shootings are events where at least four people, excluding the shooter, are injured or killed, according to The Gun Violence Archive. As of August 27, the archive found 642 mass shootings in 2022, 660 mass shootings in 2023, 503 in 2024 and 286 year-to-date in 2025.

Although some other mass shooting trackers use narrower methods and raw numbers, some also show a decline between 2023 and 2024.

Laws’ impact on mass shootings is still a mystery, though.

Gun violence experts expressed caution in putting a blame on the 2022 law for the decline in mass shootings for a number of reasons:

There were many elements to the 2022 law. According to Jaclyn Schildkraut, executive director of the Regional Gun Violence Research Consortium at the Rockefeller Institute of Government, it’s difficult to attribute the law’s decrease to the law because it “had so many different parts,” including funding for “red flag” laws at state levels. When a person poses a threat to other people, red flag laws allow courts to temporarily remove their weapons.

According to Schildkraut, demonstrating a connection would require examining changes over a number of different initiatives over a much longer period of time.

Mass shootings are uncommon. Because they are statistically very uncommon, “it is difficult to distinguish change due to random variation over time, such as the Bipartisan Safer Communities Act,” said Veronica Pear, assistant professor at the University of California, Davis.

According to Terry Schell, a senior behavioural scientist at Rand Corporation, a nonpartisan think tank, “it is extraordinarily difficult to determine, empirically, if any national law caused a particular shift in a rare outcome. All that would remain true is that something had to have happened in 2023 to reduce mass shootings, even if the rate had fallen to zero in the years immediately following the passage. This law might exist, or something entirely entirely different.

According to Schell, data that would allow researchers to exclude alternative causes is necessary for making claims about causation.

Our decision

According to Murphy, “Mass shooting decreased as we finally passed a gun safety bill in 2022.”

He cited data from the Gun Violence Archive, which showed a decline of 660 mass shootings in 2023 from 503. The Bipartisan Safer Communities Act was signed into law by Biden halfway through 2022.

Experts in the field of gun violence said they are unaware of research that examined the effect of the law on the number of mass shootings. They urged caution because the law contains a lot of components, and it’s difficult to quantify how many of them affect mass shootings.

Important details are left out in the statement, which is partially accurate. It is half true, we think.