Deputy Keith Ho says the officer tried to stop the suspect but he fled.
Ho says the suspect then crashed the car in an alley, and put the car in reverse to try to run over the officer. The officer fired his weapon once, hitting the boy in the upper torso.
The suspect's name and age have not been released.
Police realized after the shooting that the vehicle was stolen from San Dimas.
- Get more local news headlines from the Inland Empire
- Have a news tip? Send your tips, video, or pictures