Gilgo Beach Suspect’s Home Held a 279-Weapon Arsenal and a Walk-In Vault

Rex Heuermann, the Long Island architect charged in the Gilgo Beach serial murder case, kept 279 weapons in his rundown home, most of them in a basement vault big enough to walk into, the authorities said on Tuesday.

At a news conference outside Mr. Heuermann’s ranch house, where the authorities have been collecting evidence since the arrest, the Suffolk County district attorney, Raymond A. Tierney, said that his team was wrapping up its search after more than a week of searching and seizing items. Mr. Heuermann had lived with his family in the dilapidated one-story house with the unkempt yard on First Avenue in Massapequa Park, N.Y., for years, commuting to his architectural consultancy in Manhattan.

The suspect’s now-estranged wife and two grown children have vacated the premises, and crime scene officials have spent the week digging up the backyard and removing items ranging from large pieces of furniture to small bags of household possessions. As they’ve worked, the house has become something of a tourist attraction for true crime fans and a daily encampment for news crews covering the case.

Mr. Heuermann, 59, was arrested on July 13 and charged in connection with the killings of young women whose bodies were dumped in the thick overgrowth along a stretch of Ocean Parkway along Gilgo Beach on the South Shore of the island. Mr. Heuermann has been charged with killing Amber Lynn Costello, 27; Melissa Barthelemy, 24; and Megan Waterman, 22. He is the prime suspect in the murder of Maureen Brainard-Barnes, 25.

He is being held without bail and has pleaded not guilty.

Their bodies were found in 2010 about a 20-minute drive from the Massapequa Park house, near one another and similarly bound and wrapped in burlap. But in all, 11 bodies have been found along the miles-long stretch of beach on the South Shore, and law-enforcement agencies throughout the region have been examining unsolved cases on the possibility that Mr. Heuermann might become a suspect.

In Massapequa Park, investigators have been turning the remnants of Mr. Heuermann’s existence inside out. Mr. Tierney said at the news conference outside the house Tuesday that the authorities executed a search warrant that allowed them to use ground-piercing technology to locate “a number of disturbances” under the backyard, indicating buried objects. They excavated the objects, which will now be tested, said Mr. Tierney, who was flanked by about a dozen police officers in the midday sun.

“It’s going to be a while for the analysts to do their job,” he said, adding that much of the search was an effort to find genetic evidence linking Mr. Heuermann to crimes.

Mr. Tierney said investigators had pulled “a massive amount of material” from the cluttered house, including the arsenal in the vault, which included various long guns. The collection exceeded the 92 legal permits Mr. Heuermann held, the authorities said.

Authorities have not specified how the women were killed. Asked whether anyone might have died in the house, Mr. Tierney said, “We haven’t ruled in or ruled out anything.”

Commissioner Rodney K. Harrison of the Suffolk County Police Department told reporters the search of the house was “fruitful.” And by the end of the news conference, police command posts and evidence collection trucks that had been posted outside the house almost since the arrest were gone, but an official SUV blocked the street.

When First Avenue is reopened, anyone who loiters and blocks traffic in front of the Heuermann house will be fined $150, the police said. A work crew installed a camera on a nearby telephone pole to monitor.

The 12-year investigation into the Gilgo Beach killings was marked by dysfunction and disarray, but was reinvigorated in February 2022 when authorities announced the creation of a task force of local, state and federal investigators that focused on cellphone records.

The four women whom authorities have specifically linked to Mr. Heuermann had been contacted by different burner phones, and investigators, using mapping technology, learned the calls came from two key locations that they eventually connected to the defendant: near his Massapequa Park home and near his office at Fifth Avenue and 36th Street in Manhattan.

A break came in March 2022 when investigators discovered that Mr. Heuermann had owned a Chevrolet Avalanche truck at the time of the killings. It was the same type of truck a witness had seen parked in a victim’s driveway shortly before she disappeared.

Last month, investigators matched DNA from a hair on Ms. Waterman’s body with the DNA swabbed from discarded crusts recovered from a pizza box that Mr. Heuermann had thrown out.

On Tuesday, Mr. Tierney said much of the investigation so far had focused on the so-called Gilgo Four. He said his team was “working toward” filing cases in the fourth case, all of which could take time.

“A 13-year-old cold case doesn’t get solved in a matter of weeks or days,” he said.