A teen girl, Amanda Bergstrom, comes home to find her family murdered in Winona, Minn. The unsub slashes up the surviving girl's photo. The unsub knows his way around the Bergstrom house. After reviewing the Bergstroms' skeletons, the BAU figures out that the unsub is attacking not a specific family, but families in general. Then another family is murdered, with a teen boy left alive. The team describes the unsub as a family annihilator, who is leaving the object of his rage alive to psychologically torture them. Garcia is combing through the teens' social media for clues, and discovers they were both bullies. The team puts the families of other bullies in protective custody. But Alvez and JJ find a dead teen boy, Austin Settergren, also a bully, and decide the killer isn't following the same pattern any longer. The squad decides that the unsub is a juvenile. At the school, there's a support group forf kids that have been bullied called the Anti-Terror Squad. The BAU tracks their phones, and find they've been abducted by Kyle Ecklund, a member of the team. Kyle took his friends to the outdoor court where he had originally been bullied, and pulls a gun on his friend, Zach, when the BAU rushes the court.. Prentiss talks him into surrendering.