Here's a thought, MOO -- if there's a knock at my door, even late at night, and I live on a busy stretch of highway known for lethal accidents, if I look out my bedroom window and see a lone individual at my door, and no car in my driveway, my guard would go WAY down. I would ASSUME car accident not homicide-about-to-happen. Perhaps James started to open the door when he caught sight of the weapon and shouldered his weight into the door to get it shut and protect his family.
I wonder what the vehicles of interest were doing at 1 am.... coming? going? speeding? slowing?
And what was troubling to the neighbors' dog that night, just after 1 am that fateful night?
Just my thoughts as I think them...