Gilgo Beach murder suspect Rex Heuermann on suicide watch in jail

Rex Heuermann, the Long Island architect arrested last week for the decade-old Gilgo Beach serial killings, is on suicide watch in jail, authorities said.

Heuermann, 59, of Massapequa Park, was placed on suicide watch while in custody at the Suffolk County Correctional Facility, a Suffolk County Sheriff’s Office spokesperson Victoria DiStefano told the Patch on Monday.

Heuerman is “being evaluated by the county’s mental health staff who generally make the determination to place an inmate on suicide watch,” DiStefano clarified.

DiStefano declined to comment on whether Heuerman, who was arrested at his office on Manhattan’s 5th Avenue last Thursday night, is being held at the county’s maximum security facility in Riverhead.

Notable former inmates of the infamous jail include “Amityville Horror” family annihilator Ronald DeFeo and serial killer Joel Rifkin, the outlet said.

Heuermann was charged on Friday with three counts each of first and second-degree murder in connection with the deaths of Melissa Barthelemy, 24, Amber Lynn Costello, 22, and Megan Waterman, 27.

All three women’s remains were discovered in the marshes along Ocean Parkway near Gilgo State Park in December 2010.

After an extensive investigation, authorities identified the married father of two last year after a vehicle registration search showed that he owned a first-generation, dark green Chevrolet Avalanche previously linked to the unidentified killer, court documents revealed.

Old Google Maps views show that the vehicle was often parked outside the South Shore native’s rundown Massapequa Park home, which is just about 20 minutes from where the victims’ bodies were found.

Mobile phone bills subsequently tied Heuermann to burner phones used to contact the Gilgo Beach victims, the investigators said.

The Berner High School graduate allegedly used one of the phones to place a disturbing call to Barthelemy’s teenage sister shortly after the Buffalo native vanished in 2009.

“Do you know what your sister is doing? She’s a whore,” the man told the then-16-year-old.

A slew of additional evidence against Heuermann – including gruesome porn searches and a fake Tinder account – eventually led police to test his DNA found on a discarded pizza crust.

The sample was matched to a male hair found on the burlap used to wrap Waterman’s body, the bail application stated.

In the days after his arrest, authorities searching Heuermann’s home uncovered an “arsenal” of up to 300 guns stashed in his basement, a source familiar with the case told CNN.

Records indicated that Heuermann only had permits for 92 of the firearms.

Police have also targeted the storage unit Heuermann kept in Amityville, where they are specifically searching for body parts or other “trophies” from the victims, officials said.

On Monday, authorities were spotted removing a troubling portrait of a battered woman with a distinctive black eye from Heuermann’s home on 1st Avenue.

A “Playboy” magazine and a poster from the television show “M*A*S*H” were also seen being loaded into evidence trucks.

In addition to material evidence, news of Heuermann’s arrest sparked several witnesses to come forward about upsetting alleged encounters with the architect.

“I even gave him a ride to his home in Long Island from Brooklyn. At one point on the drive we talked about the Gilgo Beach murders — we even discussed the burlap and why someone would use that,” one former client told The Post of a past interaction with Heuermann.

“In retrospect, thinking about that conversation, it’s just bone-chilling.”

At the time of his arrest, Heuermann had run RH Architects in New York City for over 25 years.

He was taken into custody by plainclothes officers on Thursday night.

“Is it in the news?” he reportedly asked the officers while he was being processed on multiple murder charges.

A total of 11 bodies, mostly women, were found in the Gilgo Beach area starting in 2010.

In addition to the deaths of Barthelemy, Costello, and Waterman, Heuermann remains the prime suspect in the murder of Maureen Brainard-Barnes, who was the first of the so-called “Gilgo Four” to go missing.

It is unclear if he is tied to any of the other Gilgo bodies, including that of Shannan Gilbert, whose May 2010 disappearance sparked the search that uncovered the other victims. 

As of Tuesday morning, Heuermann is being held without bail while police continue their investigation into the former cold case.