Cops find walk-in vault in ‘fruitful’ search of Gilgo Beach suspect’s Long Island home

Investigators uncovered a massive walk-in vault — but no soundproof room — during their ongoing search of suspected Gilgo Beach killer Rex Heuermann’s Long Island property, police said Monday.

Suffolk County Police Commissioner Rodney Harrison called the 12-day search of Heuermann’s Massapequa Park property “fruitful,” saying he hoped cops will be able to wind down their work either Tuesday or later in the week.

“There have been some things that we’ve had to take into custody… That makes it fruitful,” he told reporters.

Harrison said earlier reports of a soundproof room being found in the basement were “misconstrued.”

“There’s not a soundproof room. There is a vault where he secured numerous amounts of guns,” Harrison said, referring to Heuermann.

“Somehow I believe the soundproof room and the vault — the message got misconstrued.”

He said the vault was secured with a “big iron door.”

Heuermann, 59, is charged with three counts of murder in connection to the murders of Amber Lynn Costello, 27, Melissa Barthelemy, 24, and Megan Waterman, 22 — whose remains were found along a marshy stretch of land in December 2010.

He is also the “prime suspect” in the death of Maureen Brainard-Barnes, 25, whose remains were also found at the site — among 11 bodies in all unearthed at Gilgo Beach in 2010 and 2011, most of them victims of unsolved crimes.

Heuermann, a married father of two and an architect with offices in Midtown, Manhattan was arrested on July 13 and charged in the 13-year-old cold case.

State and county cops have since been combing through the hulking suspect’s property — removing as many as 300 guns and other items from the house, with three police cadaver dogs brought in on Sunday.

Police are also digging up Heuermann’s backyard with a backhoe and using a ground-penetrating sonar device to identify potential buried evidence or possibly bodies.

Harrison, a former NYPD chief who was sworn in as Suffolk County police commissioner in January 2022, said there is no evidence so far linking Heuermann to the other bodies.

“It’s hard to say. Once again this person has been at large for a very long period of time,” Harrison said.

The commissioner reopened the case last year, creating the joint Gilgo Beach Task Force that he said he planned to keep in service and continue the investigation into all of the bodies found along the South Shore.

“We’ll keep the task force together,” Harrison said. “We’ll keep it intact. We’ll see if there are any other victims on Ocean Parkway or anywhere else throughout Long Island.”

Harrison formed the unit after taking office, with the squad identifying Heuermann as the suspect by March 2022 — in part by following up on a 2010 tip from a witness whose dormant lead eventually helped land Heuermann in handcuffs.

Police in South Carolina, where Heuermann owns a secluded property, confirmed last week that they are investigating any links between the architect and a missing woman there.

Cops in Las Vegas, where the accused killer owns a timeshare, are also scouring missing person files.

Heuermann pleaded not guilty at his arraignment and is being held without bail.