Los Angeles (CNN) -- A father shot and killed his 5-year-old twins and their mother during an argument while driving the family on a Los Angeles street Saturday night, investigators said.
Salvador Acevedo, 45, later killed himself with the same handgun after dropping off three older children at a relative's home, according to a Los Angeles Sheriff's spokesman.
Acevedo "became involved in a domestic dispute" with his girlfriend, 33-year-old Iris Oseguera, while in the car, Sgt. Harry Drucker said. "Acevedo produced a handgun and shot Oseguera and their twin children, striking each victim in the upper torso."
The three adolescent children who were riding in the car were not wounded, he said.
"Acevedo dropped the adolescent children off at a relative's home and drove away," he said. "The children told an adult about the incident and they alerted East Los Angeles Sheriff's Station."
When deputies locate Acevedo's car, they found him "suffering from an apparent self-inflicted gunshot wound and the three injured victims inside of the vehicle," Drucker said.
Both parents were dead at the scene, while the twin children were taken to a hospital, where they were pronounced dead, he said.