In addition to a "random" abduction, there is also the possibility of abduction by a stalker or other person who had specifically targeted LS. I wonder if she ever thought she might be followed, or thought someone was watching her, etc. And if she did, did she ever mention it to any of her friends or acquaintances.
I know there has been little or no attention given to such a theory, but I think it is important that no possible scenario be eliminated when there are so few facts to go on.
I think stalking is very unlikely because a stalker would have no way of knowing when she was going to leave CR's, MB's and JR's apartments. How would a stalker know she was going to go home alone at 4 am in the morning?