LONG ISLAND, NEW YORK: Rex Heuermann, the Manhattan-based architect has been charged in the serial killing of Gilgo Beach, involving four young prostitutes in a decade-old case. The father-of-two is charged with three counts of first-degree murder and three counts of second-degree murder in the deaths of Melissa Barthelemy, Megan Waterman, and Amber Costello. Meanwhile, he remains a prime suspect in the death of Maureen Brainard-Barnes. The victims’ bodies were found between 2007 and 2010, near Ocean Parkway in Long Island, New York.

The 59-year-old architect was traced by investigators with the help of burner phones. Apparently, they also found a piece of his hair was allegedly at the bottom of a burlap bag used in wrapping Waterman’s body. Cops also linked Heuermann’s Chevrolet Avalanche which was spotted at the time of Costello’s disappearance. "That individual was identified as a person who was between 6'4" and 6'6", a large man, thickly built, not necessarily overly muscular, but just a naturally big person with glasses, white and dark hair," District Attorney Ray Tierney said. "Also of significance was the fact that he was driving a dark-colored black first-generation Chevrolet Avalanche."

Why did Rex Heuermann keep track of victims' families?

In a chilling revelation, Suffolk County District Attorney Ray Tierney shared that Rex Heuermann was keeping track of not just the victims, but their family members too. “He was compulsively searching pictures of the victims, but not only pictures of the victims, pictures of their relatives, their sisters, their children, and he was trying to locate those individuals,” he said during a press conference.

The DA shared that during the investigation it was found that the alleged serial killer continued to follow the case and looked for articles about the task force that was investigating the murders. “In a 14-month period, he had over 200 searches pertaining to the Gilgo investigation,” Tierney said. “Not only was he looking at investigative insight, he was trying to figure out how the task force was using cell phones to try to figure out what’s happened. What are the developments with regard to the task force.”

'[We] 'don't know' if he ever stopped killing'

Earlier in the day, aerial footage taken by a drone showed forensic investigators in the backyard of his Massapequa Park home, looking for further evidence, as reported by People.

Katherine Ramsland, an expert in forensic psychology, suggested that the number of victims may rise as the investigation deepens, “[We] 'don't know' if he ever stopped killing, adding that 'all we know is what he's a suspect in right now.”