Gilgo Beach Murder Suspect May Have Kept Trophies of Victims — as Police Allege Disturbing Internet Searches

Rex Heuermann, the man police allege is the Long Island Serial Killer, may have kept trophies of his victims, according to authorities.

“Whatever it is, whether it’s something that he kept intentionally or something that he didn’t even realize he kept, we hope that somewhere in that house it’s located and we could find it," Suffolk County District Attorney Ray Tierney tells PEOPLE.

Tierney says authorities are “in the process of gathering a massive amount of digital evidence and trace evidence. We’re undergoing that process so we just have to wait for that to play out. Then at the end, we’ll see what we get.”

ABC7 reported that earlier this week investigators served multiple search warrants on Heuermann’s home and two nearby storage units and have asked a law enforcement agency in South Carolina to seize a vehicle police say may be linked to the case.

On Friday, 59-year-old Heuermann, an architect and married father of two, was charged with three counts of first-degree murder and three counts of second-degree murder in the deaths of Amber Costello, 27, Melissa Barthelemy, 24, and 22-year-old Megan Waterman.

He is considered a prime suspect in the death of 25-year-old Maureen Brainard-Barnes.

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All four women had worked as online escorts and had been missing between 2007 and 2010. Their bodies were found along a half-mile stretch at Gilgo Beach on Long Island, N.Y., in December 2010.

Investigators have since uncovered the remains of at least 10 people along Gilgo Beach, though they have said not all of them are believed to be connected to the same killer.

The killer allegedly used four separate burner phones to contact the women. “He would buy the burner phone, call them, and lure them out to Massapequa,” claims Tierney. “Then he would murder them, and then he would discontinue the use of the burner phone. He did that four times.”

Tierney alleges Heuermann was “disciplined” in his use of the phones — but cell sites eventually “betrayed” his locations in Massapequa Park and Midtown Manhattan.

However, it was “a comprehensive review of every item of evidence” in March of 2022 that eventually led to the discovery of a Chevy Avalanche that was owned by Heuermann at the time of the slayings.

Chevy Avalanche Was Break in Case

According to court documents obtained by PEOPLE, “a witness to the disappearance of Amber Costello identified a first-generation Chevy Avalanche as the vehicle believed to have been driven by her killer.”

At that point, a task force detective used motor vehicle records to track down Heuermann and the Chevy Avalanche.

"They found his car, and they found his address, and then they found out his physical description, and then they found out where he worked," says Tierney. "And every time they dug further, you were getting more associations, which obviously got people excited.”

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Tierney says investigators then needed a DNA sample from Heuermann to compare to a male hair recovered from the bottom of the burlap used to wrap Waterman's nude body.

“Now we have something to compare it to, we just need to get a DNA sample, so the Suffolk County PD and the FBI surveilled the defendant,” he says.

Authorities secured abandoned DNA samples from a pizza crust that Heuermann allegedly discarded in a Manhattan trash can and from 11 bottles taken from the trashcan outside his home.

On June 12, a lab determined that the mitochondrial DNA profiles from the male hair found on Waterman and a DNA swab from the pizza crust were "the same," according to the court papers.

They also matched other hairs found at the scene to Heuermann’s wife, who had been out of the area when each of the women disappeared, which led detectives to surmise they got there because of her close proximity to her husband and not because she was involved in the killings.

'Obsessively Looking at the Victims'

Authorities allege that once Heuermann was identified, investigators tracked his burner phones and discovered additional burner phones, fictitious email accounts and fictitious identities that he was using.

“We saw all this, really sort of concerning searches that he was undergoing,” says Tierney. “In a 14-month period, over 200 times, he’s searching for information about the Gilgo investigation. He’s trying to figure out what we’re up to.”

According to authorities, included in his searches were: “why could law enforcement not trace the calls made by the long island serial killer” and “why hasn’t the long island serial killer been caught.”

Investigators also allegedly found hundreds of internet searches about raping and torturing women, child porn and rape porn such as “girl begging for rape porn” and “torture redhead porn” as well as searches for his victims and their families.

“He was obsessively looking at the victims, but he’s also looking at the victim’s siblings,” claims Tierney.

Heuermann also allegedly seemed to be fascinated by other serial killers and sleuthed online for “11 currently active serial killers,” and “8 Terrifying Active Serial Killers (We Can’t Find).”

He also allegedly used these fictitious accounts and burner phones to contact sex workers.

“This was not good,” says Tierney.

Tierney says authorities knew they had to arrest the suspect quickly, and decided to do it away from his home since he owned 92 gun permits.

"I’d say he was pretty surprised," says Tierney about Heuermann's July 13 arrest near his office building in Manhattan.

“I think he lived this double life, and he used the anonymity of phones and computers to shield himself from the rest of society," says Tierney. "Unfortunately for him — and fortunately for the rest of us — he wasn’t successful.”

Neighbor: 'It's Very Surreal'

Meanwhile, neighbors in the usually sedate village of Massapequa Park who woke up on the morning of July 14 to find an army of investigators searching Heuermann’s ranch-style house are in disbelief that an accused serial killer has lived in their midst.

"It's very surreal," says neighbor Michael Musto. "I'm still trying to process it all. I just observed law enforcement take out coolers from his house. God only knows what's in those coolers. I don't want to imagine it. And then they also took away all of his vehicles. I just observed a flatbed, basically hook up all of his cars, drive away with them."

Musto described Heuermann as a recluse and an antisocial person. Musto's sister, he says, would try to speed her pace up when she walked the dog past the house, with its sagging front porch and dilapidated wood shingles.

"She would get a very, very uncomfortable feeling just walking past the house," he says. I don't know if she has a sixth sense that she picked up on. But it was very strange. Very strange."