Witnesses told Riverside police that a 2008 Ford Mustang and an older, orange Acura Integra or Honda Prelude were traveling at a high-rate of speed on northbound Magnolia Avenue, approaching Nelson Street, around 2 p.m.
At that time, a Chevrolet Malibu was waiting at a stop sign waiting to turn onto Magnolia Avenue. As the Malibu pulled out, it was struck by the Mustang.
Carly Rodriguez, who was sitting in a booster seat in the rear of the car, was critically injured and taken by ambulance to Loma Linda University Medical Center. The driver, the girl's father, was not injured.
The driver of the Mustang apparently approached the occupants of the car he struck, but then fled on foot.
"When he got out of the car, he started approaching the other vehicle and was yelling obscenities, blaming them for the accident," said witness Scott Gundurm. "When he saw that there was a girl on the ground, he turned around and left."
It was later determined that the Mustang had been stolen from Madison and Evans streets, less than two miles away, moments before the crash.
The driver of the car believed to be racing the Mustang continued driving on Magnolia Avenue.
The driver of the Mustang was described as a Hispanic male in his mid-to-late 20s with roughly shoulder-length black hair. He was wearing a white shirt and black pants.
Anyone with any information is asked to contact Riverside police detectives at (951) 826-8722.
The victim's age was previously reported as 5. Authorities later confirmed she is 4 years old.