In a reprieve from years of the nation's harrowing mass killing incidents, the United States is on track to record its lowest rate of such deadly events in two decades, according to one group of researchers tracking the data.
Were 17 massacres, 14 of which were committed with firearms.recorded this year, according to a database maintained by Northeastern University in partnership with the Associated Press and USA Today. While that number may increase in December, it is the lowest since the database was created in 2006. And it represents a significant decline from previous years, including 2023, which saw more than three dozen similar incidents.
Northeastern's database tracks incidents in which four or more people, not including the attacker, were intentionally killed in a 24-hour period. Most mass violence involves the use of firearms, which is the subject of the chart accompanying this article. But the database also tracks other mass shootings, such as stabbings and the use of vehicles to attack pedestrians.
Why did we write this
As the annual number of incidents of mass violence rises and falls, even a small reprieve from the bloodshed in a country where thousands of killings occur each year underscores changes in policy.
The database offers important—but only one—information about the country's fight against violence, which is not always fatal. Another organization, e.g. Gun Violence Archive, counted 381 mass shootings this year, compared with 503 for all of 2024. This group defines a mass shooting as an event in which four or more people are shot, although not necessarily killed.
Some experts attribute some of the progress to recent anti-crime policies both locally and nationally, as well as increased school security measures. Part of the shift may also represent what statisticians call “reversion to the mean,” suggesting a return to more average crime levels after a sharp rise in previous years.
Although the long-term trend in mass killings is characterized by peaks and valleys rather than a clear pattern of rise or fall, the latest data shows a decline.
“The overall picture of violent crime in the United States seems to be getting a little better,” says Adam Lankford, author of “The Myth of Martyrdom,” a book that explores the motives behind violent riots.
Postponement but constant challenge
For government officials and citizens alike, any evidence of a decline in mass violence is welcome news—a reprieve from the bloodshed in a country where tens of thousands of gun deaths occur each year.
Determining what factors cause increases and decreases in such violence is challenging, especially when attempting to draw scientific conclusions. Criminologists are still debating why homicide rates fell sharply in the 1990s.
While other violence databases also suggest an overall decline in mass violence, Professor Lankford notes that the types of deliberate public mass killings that tend to change American behavior have not decreased, according to the new data, with much of the shift attributed to a decline in mass killings in or near people's homes.
Moreover, he says, the rise in targeted political killings may well offset any sense of relief from the slowdown in mass killings.
Violent events that create fear and motivate responses include “shootings at schools, shopping malls and movie theaters,” says Professor Lankford, who is also a criminologist at the University of Alabama. This means that “the type of mass killings that have declined the most is not the type of mass killings that Americans seem to fear the most.”
However, one of these categories has seen a significant decline recently.
Schools have seen some of the nation's most tragic mass shootings in past years, including at Sandy Hook Elementary School in Newtown, Connecticut; Robb Elementary School in Uvalde, Texas; and Marjory Stoneman Douglas High School in Parkland, Florida.
Melanie Stetson Freeman/Staff/File
There have not been any acts that would qualify as massacres on the school campus this year.
Part of this shift may be the result of changes in school policies and practices.
For example, twenty-two states now require school threat assessment teams, and the Safe Communities Act of 2022 provides millions of federal dollars to support gun violence prevention programs.
“The case can be made that we see more threats, but not as many attacks, as we do in schools that have implemented threat assessment programs,” says Eric Madfis, director of the Violence Prevention and Transformation Research Center at the University of Washington in Tacoma.
“When I talk to people who have stopped school shootings, a lot of it is a violation of the student code of silence when reporting what happened,” he adds.
As part of this, “we have moved from a zero-tolerance policy, where we punish a child who accidentally brings a knife to school, to examining the nature and content of threats,” he continues. “Do they have the ability to pull it off, access to weapons, plans for who they're going to kill, when and where? We've seen amazing results” from this shift.
A return to normalcy after the whiplash caused by the COVID-19 pandemic may also be a contributing factor, along with an overall decline in violent crime rates since 2022.
Renewed police focus on curbing gun proliferation in high-crime areas and making arrests as homicides increase could also have a positive impact.
Experts say improved emergency care also leads to fewer deaths in mass shootings.
For example, the shooting in Minnesota earlier this year does not meet Northeastern's definition of a mass murder, although approximately 20 people were injured. Why? Despite the enormous tragedy of the incident that killed two children, experts say the quick actions of Minneapolis emergency responders likely saved many lives.
Question of care
Sociologists suggest that one important causal factor in violent crime throughout American history has been the level of social well-being, including political activity and self-expression.
After the American Revolution, the expansion of suffrage, a vibrant economy based on business ownership, and a general sense of patriotism contributed to the New England region achieving the lowest murder rate in the Western world in the late 1700s.
Conversely, from the deadly 1960s riots in several U.S. cities to the violence that accompanied some protests following the killing of George Floyd in 2020, the prevalence of protest-related violence has been one of the historical predictors of high homicide rates in the modern era.
However, there have been numerous protests in the US this year, including large “No Kings” demonstrations, without a spike in killings. The protests were defined not by violence, but by social commentary (placards, costumes and speeches) directed at politicians, most notably President Donald Trump.
Party echo chambers may also mask changes in Americans' feelings about their own prospects and the prospects of the communities in which they live as partisan affiliation increases.
“The key to a low murder rate is successful state building” writes Randolph Roth, author of American Murder, in a 2024 research paper on why murder rates rise and fall.
At the same time, the persistently high number of gun deaths overall—including suicides, which far outnumber homicides—challenges the notion that general prosperity suppresses mass violence, at least for now.
Just because society may be getting better at preventing mass shootings does not mean the threat is decreasing, Professor Lankford said. He cites targeted political violence and the U.S. Surgeon General's 2023 report on the epidemic of loneliness and isolation as issues of concern.
“If anyone interprets this [dip in mass killings] like, 'Congratulations, we've stopped shootings in schools or workplaces,' then they're just wrong about what the data shows,” he says.
