The person of interest being held in connection with the Wisconsin Christmas parade rampage that left five people dead and dozens injured may have been involved in an earlier incident involving a knife.
Senior law enforcement officials told NBC News that the person, who may have a significant criminal history, was fleeing the earlier incident right when he plowed through the parade in Waukesha about 4:40 p.m. local time.
The driver blew past police barricades and mowed down a group of marchers, killing five people and injuring dozens, including children, officials said.
Police Chief Daniel Thompson said terrorism has not been ruled out as a motive.
Witnesses had reported that shots were fired by the driver, but police later clarified that an officer discharged their weapon at the vehicle.
No bystanders were struck by the gunfire, Thompson said.
President Joe Biden has been briefed on the incident, a White House official told CNN.
“The White House is closely monitoring the situation in Waukesha and our hearts go out to everyone who has been impacted by this terrible incident,” the official told the network.
“We have reached out to state and local officials to offer any support and assistance as needed.”