Image Credit: Getty Images Rex Heuermann - the architect accused in the long-running Gilgo Beach killings - has now pleaded guilty to multiple murders tied to the case. He had previously been charged in connection with the deaths of seven women: Megan Waterman, Melissa Barthelemy, Amber Costello, and Maureen Brainard-Barnes, Jessica Taylor, Sandra Costilla and Valerie Mack. Heuermann was arrested in July 2023 and initially pleaded not guilty, but his April 2026 guilty plea marked a major turning point in a case that has gripped Long Island since the 1990s.