Police responded to Quincy Alley, to the rear of 11 Tennessee St. and adjacent to 810 Butte St., just after 1:30 p.m. after numerous callers reported a shooting, Lt. Lee Horton said.
An officer arriving on the scene found a female victim down in the alley and witnesses who directed him to the suspect, standing behind a parked car.
As the officer approached, the suspect pointed a handgun at him, prompting the officer to fire his own gun in self-defense, Horton said.
Paramedics pronounced the female victim, a 48-year-old woman with multiple gunshot wounds, dead at the scene.
The male suspect was pronounced dead at Kaiser Hospital in Vallejo.
Investigators have determined the man and woman were married, Horton said. The suspect owned a business nearby on the first block of Tennessee.
The names of the suspect and victim are being withheld pending notification of next of kin.
The officer-involved shooting will be jointly investigated by the Solano County District Attorney's Office and the Vallejo Police Department, according to county protocol. The officer has been placed on administrative leave.