What was Loomis and Ann's location at the time of the shooting?

Ann was outside in front of the house. Loomis was watching her, rifle in hand, from the upstairs window.

I stood there in front of the house as I had before, watching the front door, thinking I would go and knock if he did not appear. There was a sharp snapping noise. I was wondering what and where it could be when I felt a hard tug on the leg of my blue jeans and a sting of pain in my right ankle. The noise came again. Not until then did I look up and see the shiny blue rifle barrel, very thin, the upstairs window six inches open and his face behind it, partially hidden by the curtain.