Double tap maybe. However I was taught that the shots should be fired center mass. What you are aiming for is the triangle between the chin and the nipples. The reason is that center mass is the largest area and biggest size target. You are aiming for the triangle as Any shot there is a kill shot. If you miss the triangle then you will still hit the target in the body. A head shot is specifically not what your taught to shoot in an emergency shooting situation cuz it is a small, hard to hit target. A head shot is for things like the mozambique drill- two shots to the chest and one in the head.
here Arm AND head shot. Seems unlikely if you think it's an intruder. Like both shots on a double tap are into center mass. Sounds like he hit her in the arm and did the coup de gras with a head shot.