Long Island investigators have identified the remains of six cold case victims whose deaths date back as far as 50 years, including one woman who may have been killed by the notorious Jersey Shore “Thrill Killer.”
Investigators used advanced DNA testing—the same technology that helped authorities arrest alleged Gilgo Beach serial killer Rex Heuermann in 2023—to identify the previously unidentified victims. Three of the six are believed to have been murdered.
“We’ve given back their names,” Suffolk District Attorney Ray Tierney told reporters Thursday. “We have made full progress in restoring the identities of these individuals, providing answers to their loved ones and advancing the pursuit of justice on their behalf.”
One of the victims was a woman known for decades as “Montauk Mary.” The elderly woman was found in the coastal town in 1978 with four gunshot wounds to her chest. Investigators identified her as 73-year-old Sofia Margherita Marrone, and they believe she may have been killed by serial murderer Richard Biegenwald.
Marrone’s body was discovered far from her New Jersey home. She had last been seen alive days earlier, leaving Shore Memorial Hospital in the Garden State, near her residence in Pleasantville.
Investigators have not determined how Marrone ended up hours away in Montauk. They suspect she may have been targeted by Biegenwald, known as the “Thrill Killer,” who murdered at least six people along the Jersey Shore before his arrest in 1983.
Biegenwald is considered a suspect in Marrone’s death because the bullets used were the same type linked to his other killings: .22-caliber short rounds. Police stressed, however, that they cannot yet confirm he was the shooter. Biegenwald died in prison in 2008.
Another victim was 41-year-old Ramon Perez Y Rivera, who had long been identified as Raymond Doe because of a tattoo on his body. Hunters found him in Deer Park in 1976 with a gunshot wound to the abdomen. The Puerto Rico native had been living in Brooklyn at the time of his death.
Authorities also identified 27-year-old Antionette Rugg. She was found in Islip in 1978 after a dog scratched at the ground and uncovered a human skull. A belt was discovered tightly fastened around her neck.
The remaining victims were 32-year-old South Korean national Kyong-Ok Kim, 27-year-old Omelios Steward and 27-year-old German national Andreas Kupke. Kim was found in Riverhead Town in 1990, and her cause of death remains under investigation. Steward, who was found in 1990, was believed to have drowned, while Kupke was discovered in 1999 and his cause of death remains unclear.
“We have made full progress in restoring the identities of these individuals, providing answers to their loved ones and advancing the pursuit of justice on their behalf,” Tierney said.
Suffolk County still has roughly 244 unsolved death investigations dating from 1970 through 2025.
About 210 victims connected to those cases remain unidentified. Tierney said his office continues to work on identifying them and will use the same advanced DNA technology whenever possible.
