A Chevrolet Avalanche, a pizza crust and burner cellphones proved to be the critical evidence that led investigators to Rex Heuermann as a suspect in at least three of the Gilgo Beach killings. NewsdayTV's Shari Einhorn and Sandra Peddie report. Credit: Newsday Staff; Photo Credit: Suffolk County Sheriff's Office

The watershed moment in the Gilgo Beach investigation came on March 14, 2022.

That was the day a New York State investigator linked a Chevrolet Avalanche to Massapequa Park resident Rex A. Heuermann. Witnesses had seen a customer of sex worker Amber Lynn Costello in that kind of pickup the day before she was killed.

The investigator made the link just six weeks after newly elected Suffolk District Attorney Ray Tierney formed a task force, which met secretly away from the district attorney's office to not attract attention. Members of the task force — who hailed from the Suffolk Police Department, New York State Police, FBI, Suffolk County Sheriff’s Office and the Suffolk District Attorney's Office — got a breakthrough after nearly 12 years of headlines about the unsolved murders at Gilgo Beach.

The investigation that followed was built piece by painstaking piece. The task force tracked burner phones, triangulated cell site data, used advanced DNA testing on single strands of hair found on the victims’ bodies, surveilled Heuermann and picked up his DNA from a leftover pizza crust in a box he discarded in a garbage can on Fifth Avenue in Manhattan, according to court papers.

As they continued to gather evidence over the next 14 months, investigators gained critical insights into Heuermann. Authorities said in court papers that he viewed torture pornography and watched videos of women and girls being raped and murdered. He made more than 200 internet searches seeking updates on the Gilgo Beach investigation, specifically how the task force was looking into cellphones related to the case, court papers said.

He also looked up photos of the victims and their families, Tierney said.

And he continued to contact sex workers, court papers said. Task force members feared what that could mean.

There was tension within the task force, over the need to gather as much evidence as possible and keeping the public safe. It’s the kind of tension that exists in every investigation, Tierney said.

The FBI’s surveillance of Heuermann gave them some comfort, but by Thursday, the balance had tipped “in favor of public safety,” Tierney said. Authorities cut short their investigation and arrested Heuermann, an architect by trade.

At a packed news conference Friday at the sheriff’s office in Yaphank, the more than 35 assembled task force members evinced both a quiet pride in the arrest and a grim determination about what they still have to do. Heuermann was charged with only three of the killings — those of Costello, Melissa Barthelemy and Megan Waterman. He is a “strong suspect" in the case of Maureen Brainard-Barnes, but that case remains unsolved. So are the cases of the six other victims tied to Gilgo Beach.

“We’re not done,” Suffolk Police Commissioner Rodney K. Harrison said.

Harrison on Friday referred to Heuermann as "a demon that walks among us, a predator that ruined families."

Heuermann's attorney, Michael J. Brown of Central Islip, said on Friday that the case against his client is “extremely circumstantial in nature.” Brown said Heuermann, while in tears, told him: "I didn’t do this.”

The Gilgo 4

The first meeting of the task force was held on Feb. 1, 2022. Tierney told investigators they had to strip down any previous investigative work and start from scratch.

They focused on the Gilgo 4 — Barthelemy, Waterman, Costello and Brainard-Barnes, whose remains were found in December 2010 along Ocean Parkway in Gilgo Beach. Barthelemy’s remains were found after a Suffolk police officer was conducting a routine exercise with a cadaver dog. Police found the other three sets of remains two days later.

Authorities theorized from the beginning that their deaths were linked. Their bodies had been placed close to one another, all within 33 feet of the parkway. The women were all petite and ranged from 22 to 27 years old. They were similarly bound at the head, chest and legs with belts or duct tape and were wrapped up in burlap. Although there has been speculation that the burlap came from a landscaping company, it actually was camouflage burlap, the kind used in duck blinds for hunting, Tierney said.

The women were all sex workers who were missing clothing and personal possessions.

And in what would turn out to be a critical clue in the investigation, each of the women had been contacted before their disappearances by someone using a burner phone, which is a temporary phone with prepaid minutes and is not associated with a verified identity. The point of a burner phone is to remain anonymous, although it is possible to track them with specialized tools.

In the early years of the Gilgo investigation, around 2012, the FBI analyzed cellphone tower data. By comparing where the victims’ phones pinged off cellphone towers with where the burner phones pinged, analysts were able to narrow the pings to a confluence of four cell towers. They called the area of interest “the box.” They had a box in Massapequa Park, where the victims were believed to have disappeared from, and a box in midtown Manhattan, where a taunting call to Barthelemy’s sister had been made, according to Tierney and court papers.

At the time, Suffolk police zeroed in on a person of interest in Massapequa Park, someone who had a business in Manhattan. He also fit the FBI profile, which described a white, middle-aged, married man. But it stopped there. They were unable to gather enough evidence to make a case, according to a source familiar with the investigation. The person of interest at the time was not Heuermann.

In the ensuing years, the Gilgo investigation stalled, as a scandal within Suffolk law enforcement made international headlines. Police Chief James Burke went to prison in 2016 for covering up his beating of a man who stole a duffel bag with sex toys and pornography from his car. Five years later, after a highly publicized trial, his mentor, former District Attorney Thomas Spota, and his friend, top Spota deputy Christopher McPartland, were sentenced to five years in prison for assisting in the cover-up.

Timothy Sini became district attorney in 2018 after serving as Suffolk police commissioner. He announced with fanfare that he would ramp up the Gilgo Beach investigation. He ran for reelection in 2021, but lost to Tierney.         

Investigation's secrecy paramount

When Tierney took office in January 2022, he said he vowed to the victims’ families that he would take a fresh look at the case. In a swipe at Sini, who was known for his frequent news conferences, Tierney said he told the families they wouldn’t see him “calling up the media and showing up at the beach with a giant magnifying glass.”

Secrecy was paramount. “We knew the person who did the murders would be looking at us,” Tierney said.

In January, Sini, who is now in private practice, gave an interview to Newsday about the Gilgo Beach case. The interview alarmed Tierney, law enforcement sources said. Letters went out to Sini and retired investigators who had worked on the case, warning them not to talk about it, recipients of the letters said.

Electronic surveillance of Heuermann showed that he viewed the Sini interview, sources familiar with the investigation said.

Meanwhile, investigators focused on clues found at the beginning. On Sept. 1, 2010, Costello got a call from a burner phone. A man seeking to buy sex entered her house. She executed a ruse: She took the money, and then a man posing as her boyfriend showed up, enraged. The client backed off, saying he was “just her friend.” A little later, around 1:18 a.m., she received a text from the burner phone: “That was not nice so do I [sic] credit for next time.”

The same client contacted her the next night. Costello agreed to meet him. She left her house and left her cellphone. She was never seen alive again.

A witness described the man to police. He was a large, white male, about 6-foot-4 or 6-foot-6, in his mid-40s, with dark, bushy hair and glasses, like an “ogre,” according to court papers.

In addition, a witness said he saw a first-generation Chevrolet Avalanche parked in Costello’s driveway, Tierney said.

A New York State investigator did what Tierney described as a “lawman search” through databases. It is a search only specially trained personnel can do, and it involves hours of tedious searches aimed at winnowing the information to glean something usable. Finally, the investigator had a hit: A first-generation Chevrolet Avalanche was linked to a man named Rex Heuermann at the same time the women disappeared. The FBI later discovered the Chevrolet Avalanche in South Carolina.

Investigators checked further. Heuermann lived in the Massapequa Park “box” and worked in the midtown Manhattan “box.” As a white, middle-aged professional who was married, he fit the FBI profile. And at 6-4 with a bulky build and dark hair, he matched the description a witness gave years earlier to police investigating the Costello case.

The district attorney's office empaneled a grand jury and used it to issue more than 300 subpoenas. Further analysis of evidence obtained through those subpoenas found that his personal cellphone was in proximity to the target phones, according to court papers.

They had a viable suspect.

DNA advances

At the time the victims’ remains were found, their bodies were too degraded to attempt DNA matches. Investigators had to wait. They needed DNA technology to advance enough to attempt a match. It finally did.

A single female hair had been found on Brainard-Barnes and two each on Waterman and Costello. Investigators sent them to an outside lab, which determined in July 2022 that those hairs belonged to a woman who was not any of the victims, according to court papers.

On July 21, 2022, detectives retrieved 11 bottles from a garbage can outside Heuermann’s home. Further testing at a lab specializing in mitochondrial analysis linked the hairs to Heuermann’s wife. Yet she couldn’t have been near the women because travel records showed she was out of state when Barthelemy, Waterman and Costello disappeared, according to court papers.

The lab then examined a male hair found in the burlap around Waterman’s remains. After comparing the DNA on that strand of hair to the DNA on a discarded pizza crust that investigators pulled from the garbage on Jan. 26, they had a match: It belonged to Heuermann, according to court papers. 

Heuermann used a fresh burner phone before each murder and used fictitious names and emails, according to court papers. The grand jury issued subpoenas for his Google searches. Investigators checked the fake names and email accounts and turned up more than two dozen chilling searches. They included phrases like “pretty girl with bruised face porn,” “nude slave girls,” and “crying teen porn,” according to court papers.

Heuermann's Google searches revealed what Tierney called an obsessive preoccupation with the Gilgo Beach case. Among those searches were, “why could law enforcement not trace the calls made by the Long Island serial killer” and “8 Terrifying Active Serial Killers [We Can’t Find].”

Investigators also found it significant that he viewed articles about the task force investigating him.

As momentum in the case was building, rumors started to leak that the Gilgo Beach murders would be solved soon. But they remained just that, rumors. The task force was determined to preserve secrecy.

“We also didn’t want him to know how close we were getting,” Tierney said.

Heuermann, who is 59 and married with children, was arrested outside his Manhattan office on Thursday night. He was arraigned on Friday in Suffolk County Court in Riverhead and is being held without bail. Heuermann pleaded not guilty to three counts each of first- and second-degree murder.

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