Officers say the victim was the driver. The victim was shot in the head but, however, the victim was conscious. A passenger was not injured.
The shooting happened inside bore number 4, that's one of the two, westbound tunnels connecting Orinda and Oakland on Highway 24.
First reports of the shooting came in around 8 p.m. Sunday.
Preliminary reports indicate the suspect's vehicle is white in color. No other description was released.
Authorities say this was an isolated incident and there is no threat to the public.
There have been nearly 200 shootings on East Bay freeways over the past four years.