The Gilgo Beach Serial-Killing Case: What We Know

In December 2010, Officer John Malia and his police dog, Blue, were combing Gilgo Beach, a remote stretch of sand on the South Shore of Long Island, when they found human remains.

The police would later discover they belonged to Melissa Barthelemy, a tiny 24-year-old from the Bronx who worked as a prostitute and was last seen in July 2009 when she told a friend she was going to meet a client. Two days later, the police found the remains of three other women — Amber Lynn Costello, Megan Waterman and Maureen Brainard-Barnes. Like Ms. Barthelemy, they were petite, in their 20s and worked as escorts.

The discovery of their bodies, bound at the feet or ankles and wrapped in burlap, terrified residents of Long Island, devastated the victims’ families and led to a 12-year investigation marked by dysfunction and disarray. Six other bodies, including four women, a man who was never identified and a 2-year-old girl, were discovered in the following weeks.

On Friday, the police finally announced an arrest. Rex Heuermann, 59, was charged with first-degree and second-degree murder in the deaths of Ms. Costello, Ms. Waterman and Ms. Barthelemy. He is considered the prime suspect in the death of Ms. Brainard-Barnes, who disappeared in 2007.

Here is what we know about the case so far.

How did authorities zero in on a suspect?

For years, the Gilgo Beach investigation was hamstrung by dysfunction and even corruption. James Burke, a Suffolk police commissioner who at one point led the investigation, refused to work with the F.B.I., and years later the public learned he was being investigated by federal authorities for obstruction of justice in an unrelated case.

In February 2022, authorities announced the creation of the Gilgo Beach Homicide Investigation Task Force, bringing together local, state, and federal investigators.

The task force focused on cellphone records. All the women had been contacted by different burner phones, and investigators, using mapping technology, learned the calls came from two key locations that they would eventually connect to Mr. Heuermann: near his home on First Avenue in Massapequa Park and near his office at Fifth Avenue and 36th Street in Manhattan.

A break came in March 2022 when investigators discovered that Mr. Heuermann 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.

In July 2022, a detective took 11 bottles from a trash can outside Mr. Heuermann’s house. Investigators compared DNA from the bottles to DNA extracted from hairs found on some of the bodies.

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

On Thursday, he was taken into custody in Midtown. The following day, he was ordered held without bail during a brief appearance at a Suffolk County courthouse. His lawyer said outside the courthouse that Mr. Heuermann denied committing the killings.

Who is Rex Heuermann?

Mr. Heuermann, conscientious in his Manhattan job as an architect and architectural consultant, is married, has a daughter and was born and raised on Long Island, where he lived in his family home, a dilapidated one-story house with fading red paint and an unkempt yard.

He was respected by some in his field for his experience as a veteran architectural consultant and his deep knowledge of the intricacies of New York City’s building code, which made him effective at getting projects approved. Other clients found him too fastidious and combative.

In Massapequa Park, where he lived, neighbors considered him unpleasant, even menacing.

They said he would respond with silent glares when they said hello. Once, he was kicked out of a Whole Foods for stealing clementines meant for children.

On Friday, the Suffolk district attorney, Raymond A. Tierney laid out the evidence that the authorities said connected Mr. Heuermann to the crimes. He had licenses for 92 firearms and had set up a false email account that he used to search for violent pornography that showed women and children being sexually assaulted, the authorities said.

Who were the victims?

In the weeks after Ms. Barthelemy, Ms. Waterman, Ms. Brainard-Barnes and Ms. Costello were found, the details that emerged about their lives centered around their work as escorts. They were described as vulnerable women whose profession put them in the path of a serial killer.

Their families have fought to say they were more than escorts and victims. Ms. Brainard-Barnes’s sister described her as an artistic, daring free spirit, who had worked as a blackjack dealer, then as a clerk at a ShopRite. She was a mother of a young girl and boy and turned to work as an escort six months before she vanished in July 2007.

Two years later, Ms. Barthelemy, a hairdresser who had moved to New York from Buffalo, disappeared after she left her basement apartment in the Bronx and told a friend that she was going to see a man. Shortly after, her family received a series of calls from a man who admitted killing her. He used Ms. Barthelemy’s phone to make the “taunting” calls, the police said.

Ms. Waterman was 22 and living in Scarborough, Maine, when she went missing on June 6, 2010. She boarded a New York-bound Concord Trailways bus to meet a client. She was reported missing two days later, after she did not call to check in on her 3-year-old daughter.

Ms. Costello was the last of what authorities called the “Gilgo Four” to go missing. She had been addicted to heroin but had attended a 28-day rehabilitation program in Clearwater, Fla., before she moved to New York, where she relapsed, according to the Suffolk County sheriff’s department.

She had developed a ruse with her two male roommates: Ms. Costello would meet a client at her home, and after the customer had paid, one of the men would come in and claim he was Ms. Costello’s boyfriend, forcing the client to flee before any sex had occurred.

Ms. Costello tried that ruse on Mr. Heuermann around Sept. 2, 2010, prosecutors said. A witness saw a Chevrolet Avalanche parked in the driveway where Ms. Costello had been staying in West Babylon, N.Y. The witness said a tall man with “dark bushy hair” who looked like an “ogre” came out of the house and said he would call Ms. Costello later, prosecutors said in a court filing.

On the night of Sept. 2, Ms. Costello got a call from the same client and left her house. Soon after, a witness saw a dark truck pass by the house.