Shannan Gilbert's Disappearance Led Authorities to Gilgo Beach Serial Killer

The provided episode recounts the events surrounding the Gilgo Beach murders and the long and complex investigation that culminated in the arrest of Rex Heuermann. The text describes the disappearance and death of Shannan Gilbert, whose case led authorities to the discovery of multiple other victims. It then details the investigation that ultimately connected Heuermann to the murders of four women who worked as online escorts. The episode also reveals Heuermann's alleged obsession with the case, as evidenced by his extensive online searches regarding the investigation and the victims.