The incident occurred around 5:30 p.m. PST Sunday on Highway 99 near Elk Grove Boulevard, the Sacramento (Calif.) Bee reported.
The Sacramento County Sheriff's Department said a CHP officer had stopped a blue Chevy compact sedan and called for a backup unit. When backup arrived, the driver of the Chevy, described as a man in his 60s, got out of his car and fired shots, striking the backup officer. Another officer fired at the driver as the alleged gunman returned to his car and attempted to flee. The car flipped on its side after about 100 yards.
An Elk Grove police officer who responded to the scene then fired a shot that killed the driver, officials said.
The injured officer, who was not identified, underwent surgery Sunday night in Sacramento. His injuries were not believed to be life threatening, a spokesman for Kaiser Permanente Medical Center told the newspaper.