At least five people were killed and more than 40 injured, including children, when an SUV sped into a Christmas parade late Sunday afternoon in the Milwaukee suburb of Waukesha.
Witnesses described the horror of seeing people struck and lying on the ground after a red SUV drove through a series of barricades and plowed into the crowded parade.
At a press conference Sunday night, Police Chief Daniel Thompson said there is a "person of interest in custody," but would not give any other specifics.
"This is still a very fluid investigation," he told reporters.
Thompson did confirm a Waukesha police officer fired shots in an attempt to stop the driver; No bystanders were struck by the officer's gunfire.
Videos posted to social media show a red SUV speeding into the parade by a school marching band.
photo: getty images