Brooks claimed that his car had a throttle malfunction and that he had no intention of injuring anyone, but the jury did not believe him.
A man has been found guilty of killing six people last year when he drove his car into a Christmas parade near Milwaukee.
Darrell Brooks was found guilty of six counts of intentional homicide in the November 21 attack in Waukesha, about 15 miles from the Wisconsin city.
An eight-year-old marching with his baseball team and three members of the Dancing Grannies group were among the dead.
More than 60 people were also injured.
Somebody in the court shouted “burn in hell you piece of s***” as the verdicts were read to the Madison court.
The 40-year-old initially pleaded guilty by reason of mental disease but withdrew that plea in September.
The following month he dismissed his lawyers and began representing himself.
He mounted an erratic defence during a trial that included heated arguments with the judge, refusing to acknowledge his name and meandering cross-examinations.
On one occasion, after being moved to another courtroom, he removed his shirt and sat bare-chested on the table with his back to the camera.
Another day, he hid behind a barricade of boxes containing legal documents.
Brooks suggested his car had a throttle malfunction, that he had no intention of hurting anyone, and had sounded the horn to warn bystanders.
However, a vehicle inspector testified that the Ford Escape SUV was in good working order.
Prosecutors said Brooks had fled after an argument with his girlfriend but didn’t know why he drove into the parade other than being enraged.
He was out on bail from a domestic violence charge at the time.
“When you ride through a parade route and roll over children… your intent is known. That’s not an accident,” said Waukesha County District Attorney Sue Opper in closing arguments.
She said his refusal to stop showed he intended to kill people.
Brooks now faces a mandatory life sentence for each homicide conviction.