The search continued Monday for the person who opened fire on an Oakland police sergeant over the weekend.
The officer was trapped in her patrol car after colliding with another car minutes before the shooting late Saturday.
"I think this is a very cowardly attack by someone who took advantage of a situation where an officer was trapped in a vehicle to literally take a shot at a police officer," said Barry Donelan, Oakland police union president.
Police said the suspect who shot at the officer was not connected to the collision.
"Unprovoked deliberate act where the shooter walked right up to a marked police vehicle with a uniformed officer inside and fired a round into the vehicle," Oakland police spokesperson Johnna Watson said.
An emotional and tense sound clip of the moment the officer called dispatch about the shots was obtained by NBC Bay Area. In the sound clip, the officer was breathing heavily, saying that she had been shot at and that she couldn't get out of the car.
The incident occurred around 9:30 p.m. in the 1900 block of 73rd Avenue, near Weld Avenue.
Police are now looking at other ways to keep officers safe and had already started requiring officers to ride with a partner in light of officer shootings in Dallas and Baton Rouge, Louisiana.
The sergeant was in her vehicle alone because she is a supervisor.
"Now we're going to revisit the conversation about having supervisors two to a car as well," Watson said.
Donelan said police officers across the Bay Area need to be on guard. He is confident the shooter will be caught, but said the climate officers face is frightening.
"The residents of Oakland their police officers are very fortunate the outcome in that incident wasn't worse than it was," Donelan said.