Shooting last weekend At a children’s birthday party In California, which left four people dead The 17th mass killing this year – The lowest number recorded since 2006, according to A Database It is run by The Associated Press and USA Today in partnership with Northeastern University.
Experts warn that the decline does not necessarily mean that safer days are here to stay, and that it could simply represent a return to average levels.
“Sir Isaac Newton never studied crime, but he said, ‘What goes up must come down,'” said James Alan Fox, a criminologist at Northeastern University. He added that the current decline in numbers is likely what statisticians call “regression to the mean,” which represents a return to more average crime levels after an unusual rise in mass killings in 2018 and 2019.
“Will 2026 see a decline?” Fox said. “I wouldn’t bet on it. What goes down must also go up.”
Mass killings — defined as incidents in which four or more people are killed within a 24-hour period, not including the killer — are tracked in Database It is run by The Associated Press and USA Today in partnership with Northeastern University. Fox, which runs the database, says mass killings are down about 24% this year compared to 2024, which also represents a decline of about 20% compared to 2023.
Mass killings are rare, meaning the numbers fluctuate, said James Densley, a professor at Metropolitan State University in Minnesota.
“Because there are only a few dozen mass killings a year, even a small change might look like a wave or a crash,” Densley said, when in reality it is just a return to more typical levels. “2025 looks really good in historical context, but we can’t pretend that means the problem is gone forever.”
But Densley said there are some things that may be contributing to the decline, including an overall decline in homicide and violent crime rates, which It peaked during the COVID-19 pandemic. Improvements in immediate response to mass shootings and other mass casualty incidents could also play a role, he added.
“We had terrible School shooting announcement “Here in Minnesota in August, and this case doesn’t even fit the definition of a mass murder because there were only two people killed but more than 20 injured,” Densley said. “But I know from the response on the ground here, the reason only two people were killed was because of bleeding control and trauma response by first responders. And it happened on the doorstep of some of the best children’s hospitals in the country.”
Crime is complex, and academics are not adept at assessing the underlying reasons for crime rate changes, said Eric Madfis, a criminal justice professor at the University of Washington Tacoma.
“It’s multi-causal. It’s not going to be just one thing. People are still debating why homicide rates were so low in the 1990s,” Madfis said. “It is true that gun violence and gun violence deaths have decreased, but we still have very high rates and numbers of mass shootings compared to anywhere else in the world.”
More states are allocating funding to School threat assessmentTwenty-two states have legalized the practice in recent years, and that could prevent some school shootings, though it would have no effect on mass killings elsewhere, Madives said. None of the mass killings recorded in the database so far in 2025 occurred in schools, and only one mass killing was recorded in a school in 2024.
About 82% of mass killings this year involved firearms. Since 2006, 3,234 people have died in mass killings, 81% of whom were shooting victims.
The Safer Communities Act passed in 2022 includes millions of dollars in funding for gun violence protection programs, said Christopher Carretta, a former Fort Lauderdale Police Department detective and senior training specialist for Gun Safety 97%. Some states used the money to create social supports for people at risk of committing violent acts, and other states used it for things like law enforcement programs and threat assessments. This flexibility was key to the reduction Armed violence He said rates.
“It was always framed as either a gun problem or a people problem, and that was very controversial,” Caretta said. “I feel like for the first time we’re looking at gun violence as a problem on a national level.”
Emma Friedel, an assistant professor of criminology at Florida State University, said focusing on extreme events like mass killings runs the risk of “leaving the forest for the trees.” “If you look at gun deaths, whether homicides or suicides, The numbers are amazing. We lose the same number of people every year to gun violence as we saw in the Korean War. The number one cause of death for children is weapons.
“Mass killings should be viewed as part of the issue, not an outcome of interest,” she said.