Board Thread:WARNING - SPOILERS AHEAD/@comment-11593970-20130706054527/@comment-10613634-20130715214310

Scott, Allison, Stiles, Derek, Lydia, Chris Argent, Sheriff, Mrs. McCaul, Isaac, Deaton, Beta (?), Paramedic, and Random Student can all be eliminated without much hesitation. I'd be glad to explain my reasoning for anyone who disagrees. That leaves the Alpha Pack (minus Ennis), Mystery Girl, Blake, Peter, Cora, and the Principal. Of the Alphas the only one I see capable of this all is Deucalion, but I find him unlikely as he seems occupied with a lot other things. Mystery Girl I doubt seeing as she is portrayed as a good character who wouldn't kill innocent people. Ms. Blake is a strong possibilty and my favorite at this point. Peter too, seeing as he hasn't fully regained his wolf powers which would force him to kill in a human way and we all know he has no problem killing innocent people to serve his ends. Cora is a possibility with her 6 year absence, not really knowing much about her. Principal and Beta haven't been prominent but not enough to rule them out.