DAVIS, Calif. — A 22-year-old police officer on the job only a few weeks was shot and killed by a suspect who opened fire as she was investigating a three-car crash, authorities in Northern California said. The suspect, who has not been identified, was later found dead inside a home with a self-inflicted gunshot wound following a short standoff with officers, the Davis Police Department said. Police said Officer Natalie Corona was shot after responding alone to a traffic accident shortly before 7 p.m.