Yes I agree that someone would have to have been familiar with the area. Which is why I have maintained since the beginning of this case that the perp is in all likelihood a local. And part of the reason why I don't believe this crime was random, or a crime of opportunity, at least to me that seems very very unlikely.
It seems to me that the stronger possibility is that he knew her, and her him, and that he grew up in the area.
what I remain less sure of, is the nature of any knowledge of each other, as well as the motive, or even if the murder was original intentional or not.
There are many possible scenarios. But, he can know 'of her' or have met her ,but not been close at all with her. He could also be a local who didn't know her at all and this can still be impulsive crime of opportunity.