Authorities on Sunday used a backhoe to dig up the backyard of Rex Heuermann, the suspect charged in the Gilgo Beach murders. According to News 12 Long Island, investigators were also on the scene at the Massapequa Park home of Heuermann earlier in the day with a police dog and ground-penetrating radar machine. Authorities have not revealed if anything was found as part of the search on Long Island over the weekend. Heuermann has pleaded not guilty to first- and second-degree murder charges in the deaths of Melissa Barthelemy, Megan Waterman, and Amber Costello. He is also considered the prime suspect in a fourth death.