The public hasn't been a lot of help because the police, who it seems ARE grasping at straws, haven't really given us much to work with. A white van? A white box truck? Do you have any idea how many of those there are around here? I can count fifty or more on my forty-five minute commute. And we aren't given a physical description of the suspect. That may well be because no one has a description, because part of being a sniper is remaining hidden as you take your shot.
Just because the sniper is behaving like a sniper doesn't mean that this is a terrorist of the AQ variety. It simply means the sniper is pretty good at doing what snipers do, and so continues to befuddle police, who have little information to give the public.