Two days after Christmas, a mass shooting terrorizes a small town. After killing two people and wounding many more, the gunman is taken into custody. When police search for answers, they uncover the worst family massacre in U.S. history.
As the holidays begin, firefighters respond to a house fire and make a gruesome discovery. Three people have been shot dead inside. A nationwide manhunt takes authorities through Christmas, as they pursue the heavily armed murderer.
In the Season 2 premiere, a married couple are found brutally murdered in their home just before Thanksgiving, but it is uncertain if it was a holiday robbery gone wrong or if the couple knew their killer.