A former profiler for the Federal Bureau of Investigation says that investigators are likely operating off of the belief that there are more victims after the Gilgo Beach serial suspect Rex Heuermann was arrested on Thursday night.
Heuermann is charged with six counts of murder: one count of first degree murder and one count of second degree murder for each of the three victims. The victims have been identified as Melissa Barthelemy, Megan Waterman, and Amber Costello.
He pleaded not guilty to all charges during a court hearing on Friday afternoon.
Mary Ellen O’Toole, a former FBI profiler, told Fox News Digital that investigators are “probably operating off of the theory that there likely are more victims out there.”
WATCH: ‘GRIM TIDE’ ON FOX NATION
Rex Heuermann is led into Arthur M. Cromarty Criminal Complex in Riverhead, NY on Friday, July 14, 2023. The 59 year old is being charged with three counts of murder in relation to the deaths of victims found on Gilgo Beach. (Matt Agudo/Splash for Fox News Digital)
“So now they’re going back and they’re looking at cases that have been described as unsolved over the years and moving outside of New York State and New York as well,” O’Toole said.
O’Toole said it’s “not likely” Heuermann began acting out in his late-30s.
READ: CASE AGAINST REX HEUERMANN
This booking image provided by Suffolk County Sheriff’s Office, shows Rex Heuermann, a Long Island architect who was charged Friday, July 14, 2023, with murder in the deaths of three of the 11 victims in a long-unsolved string of killings known as the Gilgo Beach murders. (Suffolk County Sheriff’s Office via AP0 (Suffolk County Sheriff’s Office via AP)
“It’s more likely these serial sexual killers start to act out, if they’re going to, they start to act out in their early to mid-twenties. So they’re going to go back in time and they’re going to timeline him. They’ll go back to when he was in college and go back beyond,” she said.
Heuermann is married and has two children, working as an architect in Manhattan while living on Long Island.
CLICK HERE TO GET THE FOX NEWS APP
New York State Police remove evidence from the home of Rex Heuermann in Massapequa Park, NY, Saturday, July 15, 2023. Heuermann is charged with six counts of murder related to the bodies found on Gilgo Beach in 2010-2011. (Dario Alequin for Fox News Digital)
“I’m an architect. I’m an architect consultant. I’m a troubleshooter. Born and raised on Long Island. Then working in Manhattan since 1987,” Heuermann said in a February 2022 video interview with Bonjour Realty posted to YouTube. “When a job that should’ve been routine suddenly becomes not routine, I get the phone call.”
