Why It's Her: Melissa Hastings has always been a little mean, a little hot-headed, and a little suspicious. She's the one who buries Bethany Young. She's got ties to the N.A.T. Club. She has plenty of motive to hate the liars, since they've invariably ruined her life in more ways than one. Since she hasn't visibly appeared in the final season (yet), it could be she's been floating around in the shadows and wreaking havoc.
Why It's Not: There's one Melissa moment that's always stuck out to us. Back in season four, she has a very pointed confrontation with her sister, Spencer. "You don't understand," she says. "You never understood! I've been protecting you since it started!" The scene sticks out so much because it proves, no matter how guilty Melissa may look, her intentions are probably good. Furthermore, we've gotten no indication that Melissa has returned or will return to Rosewood. Maybe she's finally untangled herself from this whole mess.