The U.S. has recorded 17 mass killings so far in 2025, the lowest number since 2006, according to a long-running national database tracking such incidents.
The homicide and violent-crime rates nationwide after COVID-19-era spikes.
Improvements in immediate response to mass-casualty events could also be contributing, he said.
He pointed to the Annunciation Catholic Church shooting in Minnesota in August in which two students died and dozens more were injured.
"The reason only two people were killed is because of the bleeding control and trauma response by the first responders," he said. "And it happened on the doorsteps of some of the best children’s hospitals in the country."
The most recent mass killing occurred in California last week when a child’s birthday party was shot up, killing four people, including three children.
In 2019, there were 49 mass killings recorded — the highest annual total since the database began tracking cases in 2006.
The Associated Press contributed to this report.