I guess I have always thought this was someone who followed her from school a few times to get an idea of her routine...who may not live in their immediate town, a stranger to the whole family. Someone with a good enough ruse to get her to go with him, I guess, or used a gun. But not sure why she would scream away from the house and yet apparently not scream while still near the house.
If LE truly does not have a suspect, as they have indicated, then this case is increasingly becoming unsolvable, IMO. At least with Lauren S. and even Phylicia B. LE has groups of potentials suspects/POI's/witnesses who may eventually change loyalties or decide to come forward. Here, I just don't feel like they know anything.