Jordan...

 Looks to me like Jordan was the whack-job right from the beginning, meaning when she originally showed up in Salem.  I'm remembering the box she kept hidden in her apartment (the one Kate found) that contained all of those license plates.  I just can't remember if they had her picture on them or if they were someone elses she stole along her crime spree.  Clyde did such a number on her and Ben, but I think she was affected by his abuse even more than Ben.  I recall her saying to Ciera today when she was talking about Clyde something to the effect that "all those people who had to die....." and that's when I thought of those license plates she collected.  Just a thought!