Board Thread:WARNING ALL USERS False Info\Spoilers/@comment-108.81.117.0-20140311052913/@comment-99.153.200.200-20140312061818

I've been re-watching season one, and at first we are led to believe that Peter wasn't in control when he killed Laura, but in the finale, Scott tells Derek about the dead deer with the spiral in it, and that it was used to bring Laura back to Beacon Hills. Peter's nurse is the one who somehow sent the picture with the deer to Laura to lure her back so Peter could kill her and gain alpha status to help himself heal.

Kate and possibly other hunters found Laura's body and cut it in half to lure Derek back to Beacon Hills so they could use him to find the alpha, who they were searching for. That's why Kate came back to Beacon Hills. To kill an alpha.