RIVERHEAD, N.Y. (AP) — Authorities on Long Island are vowing to continue investigating a string of killings known as the Gilgo Beach murders after charging an architect in the deaths of three of the 11 victims. Rex Heuermann was charged Friday with killing Melissa Barthelemy, Megan Waterman and Amber Costello over a decade ago. He is also considered the prime suspect in Maureen Brainard-Barnes’ death. Their bodies were bound and hidden in thick underbrush along a remote beach highway across the bay from where the 59-year-old Heuermann has lived all his life. Heuermann has pleaded not guilty. Investigators have said it’s unlikely just one person killed all of the victims.