Fontana police Sgt. Robert Morris says the officer was dispatched early Tuesday to handle a domestic violence report when 38-year-old Esteban Rodriguez fled in his big-rig.
Rodriguez refused to pull over for the officer and there was a brief chase before he returned to the house, got out of the truck and headed for the door.
The officer feared for the safety of those inside and attempted to contact Rodriguez.
Morris says in a news release that Rodriguez then grabbed a large pick ax and raised it over his head, leading to the shooting.
Rodriguez is hospitalized in unknown condition. He will be booked for investigation of attempted murder.