On December 30, 2016, a woman sat down at her computer in her New Mexico home and pulled up the video feed from her surveillance system. Everyone in her neighborhood was terrified. There was a killer on the loose, and the police didn’t seem to have any idea who it could be – or what their motivation was. She scrolled back two days, and then started going through the footage frame by frame, looking for anything suspicious. For a while, nothing interesting happened. Her neighbor came home from a trip, and then some time passed, and then he left again. The woman was starting to think that what she was doing was pointless – when all of a sudden, in the corner of the screen – a dark figure appeared.