The car was described as a black 1998 Nissan Maxima with license plate No. 5TZB244. Contra Costa County sheriff's spokesman Jimmy Lee said the car was found in Danville but that investigators are still trying to locate a woman believed to be associated with the vehicle. The CHP is searching for Hispanic female suspect 35-year-old Daisi Garcia.
The shooting occurred at about 8:20 a.m. on southbound I-680 just north of the Livorna Road exit in the Alamo area. The incident shut down the highway in both directions.
The CHP reopened northbound lanes of 680 around 1 p.m. The southbound lanes remain closed, and there is no estimate yet for when they will reopen.
CHP Sgt. Diana McDermott said both the officer and the suspect were critically injured and have been taken to hospitals. She said the officer is male, but did not have additional information on him or the suspect.
McDermott said it appears the shooting was preceded by a traffic stop, and that gunfire was exchanged by the CHP officer and the suspect.
She said the CHP is also investigating the "possibility of another individual that was on scene in another vehicle."
Traffic in the area was at a standstill.
"No one's moving," said 19-year-old Kayla McGowan, of Oakland, who got stuck in the gridlock as she was headed to a class at Diablo Valley College.
Shortly before 10 a.m., she was still stopped on southbound I-680 near the where the shooting happened, and could see the yellow crime scene tape up ahead.
She said she had been in traffic for an hour and had missed her class. McGowan said motorists were getting out of their cars and socializing.
"Everyone's parked, just outside hanging out," she said.
The sheriff's office is leading the investigation into the shooting.
(Bay City News contributed to this report.)