According to the Illinois State Police, the driver of the vehicle that police tried to pull over, a 27-year-old man, was taken into custody and taken to a hospital.
Police did not say what charges the driver faces or why police were trying to stop his vehicle.
The name of the victim is being withheld pending family notification.
According to police, Rockford Police Chief Dan O’Shea has called in the Winnebago Boone County Integrity Task Force for reconstruction of the crash and investigation.
"The (Winnebago Boone County Integrity Task Force) is leading this open and on-going investigation, and no additional information will be released at this time," the Illinois State Police said in a Sunday night news release.