While searching for a missing woman on Long Island, police uncover a hidden burial ground. As families demand answers, investigators begin to realize a serial killer may have been operating unnoticed for years.

After years of stalled leads and system failures, a new task force reopens the Gilgo case, unearthing phone records, witness accounts, and vehicle clues that all point to a suspect who's been hiding in plain sight.

A year of surveillance and clandestine DNA sampling leads to Rex Heuermann's arrest. As investigators dig deeper, other victims are connected as terrifying new evidence is revealed.

A disturbing document recovered from Rex Heuermann's computer reveals what looks like a detailed murder plan. Investigators add victims and trace links far beyond Long Island. Ahead of the trial, a court ruling reveals the path forward for the case.