Two men were inside a barber shop just before 1 p.m. when two other men came in and started shooting, said Sacramento County Sheriff's Sgt. Tim Curran.
The men in the barber shop were armed and returned fire, Curran said.
The gunbattle apparently moved into the parking lot with at least one of the suspects getting into a white sedan. Curran said the gunfire continued as some of the suspects got away.
A bullet struck the 30-year-old woman in the chest just after she put her son into the child seat of her Chevy Tahoe, Curran said. The woman was pronounced dead at the scene; the child was unhurt and has been placed under child protective services.
"We believe she's a totally innocent victim," Curran said.
Four of the five men injured in the gunbattle have been taken to local hospitals, including an unidentified man with life-threatening injuries who was shot in the chest, Curran said.
A 37-year-old man, who was one of the barbers working inside the shop, was shot in the ankle. A 28-year-old man was shot in the shoulder and leg. Another man whose age was unknown suffered a leg wound.
The fifth man, a 39-year-old male, suffered a grazing wound.
Authorities have not released the identities. No charges have been filed.
"They are all being treated as victims. We do believe there's a high probability that those we are with are suspects," Curran said.
He said the strip mall in south Sacramento has been taped off and authorities have found multiple shell casings on the ground. The gunfire damaged several vehicles in the parking lot, including a Chinese restaurant across the street about 200 yards away.