WAUKESHA, Wisconsin (AP) — Investigators are looking into whether the SUV driver who plowed through a Christmas parade in suburban Milwaukee, killing at least five people and injuring more than 40, was fleeing from a crime, a law enforcement official told The Associated Press.

The joyous scene of marching bands and children dancing in Santa hats and waving pompoms turned deadly in an instant on Sunday, as the SUV sped through barricades and struck dancers, musicians and others.

One person was taken into custody after a Waukesha police officer opened fire to try to stop the vehicle, authorities said.

Investigators were questioning the person about an earlier crime, which the official described to AP as an argument involving a knife. The official, who cautioned the investigation was still in the early stages, was not authorised to discuss the case publicly and spoke to the AP on condition of anonymity.

Waukesha Police Chief Dan Thompson gave no immediate details about the person in custody or any possible motive.

The horror was recorded by the city’s livestream and onlookers’ cellphones.

The parade, held each year on the Sunday before Thanksgiving, is sponsored by the city’s Chamber of Commerce. This year’s event, the 59th, had the theme of “comfort and joy.”

Waukesha is a western suburb of Milwaukee, and about 55 miles (90 kilometers) north of Kenosha, where Kyle Rittenhouse was acquitted Friday of charges stemming from the fatal shooting of two men and the wounding of a third during unrest in that city in August 2020.