Mass killings across the United States have reached their lowest levels in almost 20 years, online data show.
The database describes mass murders as the killing of four or more people—excluding the perpetrator of the attack—within a span of 24 hours, which is in accordance with the definition outlined by the Federal Bureau of Investigation.
At least 81 people have died this year in mass killings stemming from fatal stabbings, shootings, an apartment fire, and a New Year's vehicle-ramming attack.
Fourteen people were killed on Jan. 1 after a terrorist drove a truck down Bourbon Street in New Orleans, Louisiana, accounting for the most mass fatalities in 2025.
In total, more than 600 mass killings have occurred since 2006, resulting in the deaths of 3,234 people.
The database notes that the rate of mass homicides "has remained relatively flat" over the years, given the rise in population over time, adding that the overall pattern in mass killings "is random and unpredictable.”
However, there are common themes, including the fact that most take place in private residences, not public areas, and most killers are male.
Many perpetrators are also familiar with their victims, with incidents involving family members representing nearly half of all mass killings that have taken place since 2006.
In addition to the overall decrease in violent crimes this year, James Densley, a professor at Metropolitan State University in Saint Paul, Minnesota, said that the drop in mass killings this year could be attributed to improvements in how first responders respond to mass casualty incidents.
"We had the horrible Annunciation School shooting here in Minnesota back in August, and that case wouldn’t even fit the mass killing definition because there were only two people killed but over 20 injured," Densley told the publication.
"But I happen to know from the response on the ground here that the reason only two people were killed is because of the bleeding control and trauma response by the first responders. And it happened on the doorsteps of some of the best children’s hospitals in the country."