In 2017, in San Diego, 28-year-old musician Omar Medina goes missing; his family's worst fears are confirmed when his body turns up in a barrel floating in the bay; police turn to surveillance footage to track down the people responsible.

In 2018, an explosion kills Anthony House on his doorstep; as police investigate, another bomb goes off, killing teen Draylen Mason; it becomes clear that Austin, Texas, is under attack from a serial bomber; police must use CCTV to track him down.