A 39-year-old man left his car running while he delivered newspapers in the 4100-block of North Marine Drive in the city's Buena Park neighborhood around 4:55 a.m., police said.
The man told police he saw a white Nissan pull up behind his vehicle. Before he could get back to his car, he saw a man in his early 20s get out of the Nissan, hop into his Volkswagen Passat and drive away with the child inside. The Nissan followed, police said.
Police report the boy was found in his car seat on Superior between Northwestern Memorial Hospital and Lurie Children Hospital. The boy was unharmed.
Police brought the boy's relatives to Northwestern Hospital where they were reunited and escorted by police leaving the hospital. The boy was in good condition
Evidence technicians seized the car seat and Area North detectives are investigating. No one is in custody and police are still looking for the vehicle.