Officer say the 54-year-old woman was driving in the eastbound lanes on the 10 when she was shot in the head. The woman then lost control of her vehicle, drifted into the far right-hand lanes and slammed into a wall.
Someone driving on the freeway saw the accident and called 911, but didn't know the woman had been shot. The witness thought the woman had just lost control of her car.
The woman was the only person inside the vehicle as the time of the shooting.
When CHP officers arrived at the scene they noticed that the driver's side window was shattered and realized the woman had been shot in the head. They tried to revive the woman at the scene and she was transported to Pomona Valley Hospital, where she was later pronounced dead.
The victim's identity has not been released pending notification of her family.
The CHP shut down the freeway until about 2:30 a.m. while officers combed the freeway, trying to find any clues.
Authorities still don't have any suspects. They're asking for the public's help in trying to find the suspect. They say even a partial license plate number will help them in the investigation.
Anyone with any information regarding the shooting is asked to call the California Highway Patrol at (800) 835-5247.