Three things keep going through my mind.
1. As a woman, if I were planning a murder, my first choice of weapon would be a gun. I don't know how tall MB was, but I know that I would have difficulty trying to overpower her or anyone with a hammer or axe, even from behind as I am not tall and definitely not as fit. You don't have to get very close with a gun. Aside from gun shops, would LE check any local gun ranges for someone new taking target practice?
2. If MB was targeted, how could the killer be sure that she would arrive at the church alone?
3. Somebody knows someone who walks like that, unless it was a show for the cameras.