Darrell Edward Brooks, 39, who goes by the alias MathBoi Fly, was detained by cops in Waukesha, Wisconsin after a red Ford Escape sped through the town and plowed into a crowd.

More than 40 people were injured – including 12 kids – in Sunday's horror as families and performers were celebrating an annual holiday event.

Officials said Monday 18 children were treated at the Children's Hospital of Wisconsin following the rampage.

Cops opened fire on the SUV as it plowed through a barrier and sped off.

Officers later swooped at an address in Milwaukee, where the SUV that went on the rampage was parked in the driveway.

The front of the vehicle was crumpled right up to the windscreen with its bumper and license plate hanging off.

Brooks was detained there and he reportedly complained of a sore shoulder as he was taken into custody.