For more than a decade, a string of unsolved killings known as the Gilgo Beach murders terrorized residents and confounded authorities on Long Island’s South Shore after a woman’s 2010 disappearance led investigators to find 10sets of human remains in addition to hers and launched the hunt for a possible serial killer.

Authorities announced a major breakthrough in the case last summer when they charged New York architect Rex Heuermann with murder in the killings of three of the four women who became known as the “Gilgo Four.”

In January, Heuermann was charged with second-degree murder in the fourth killing, that of Maureen Brainard-Barnes, according to an indictment. Brainard-Barnes was 25 when she was last seen in July 2007. Her remains were found along the Long Island shoreline in 2010.

Five months later, Heuermann, 60, was charged with second-degree murder in the 2003 death of Jessica Taylor and the 1993 death of Sandra Costilla, according to a bail application.

Heuermann was taken into custody in July and indicted on one count of first-degree murder and one count of second-degree murder in each of the three killings of Melissa Barthelemy in 2009, and Megan Waterman and Amber Costello in 2010, according to the Suffolk County District Attorney.

Heuermann has pleaded not guilty to all charges and “has maintained his innocence since day one,” his attorney, Michael Brown, told reporters after the fourth charge was announced.

Once Heuermann was identified as a suspect in early 2022, authorities said, they watched him and his family – getting DNA samples from items in their trash as they built a case.

Here is a timeline of the Gilgo Beach killings, how the investigation unfolded and what ultimately led to Heuermann’s arrest.

2010: Authorities find first remains in Gilgo Beach case

Police discovered the first set of female remains in bushes along an isolated strip of waterfront property on Gilgo Beach while searching for another missing woman: Shannan Gilbert, a 23-year-old from Jersey City, New Jersey, who hadn’t been seen since May 2010.

The remains of Melissa Barthelemy, 24, were the first to be discovered in the case during the search on December 11, 2010, according to Suffolk County officials. Two days later, investigators discovered the remains of three additional victims – Maureen Brainard-Barnes, Amber Costello and Megan Waterman – strewn across a half-mile stretch on Gilgo Beach.

The four women, who were wrapped in camouflaged burlap, worked as escorts who advertised on Craigslist and were last seen between July 2007 and September 2010, officials said.

After Barthelemy’s disappearance, authorities say her family received multiple taunting calls. In one of the calls, the suspect “admitted killing and sexually assaulting Ms. Barthelemy,” according to a bail application filed by the Suffolk County district attorney after Heuermann’s arrest.

Those calls, authorities say, would later help unravel the case.

2011: More remains found, including a toddler and her mother

Police said in January 2011 calls from Barthelemy’s cell phone had been traced to midtown Manhattan, with the two last calls made from around Madison Square Garden and Times Square. The caller hung up too quickly for authorities to pinpoint the exact locations of the calls, police said.

On March 29, 2011, the partial skeletal remains of another woman were found several miles east of where the bodies of the “Gilgo Four” were discovered.

The woman was first known as Jane Doe #5 before investigators identified her as Jessica Taylor, another escort whose partial remains were previously discovered in Manorville in 2003, police said.

The following month, on April 4, 2011, three more sets of remains were found on a stretch of Ocean Parkway in Suffolk County near the beach. They included a female toddler, an unidentified Asian male and a woman initially referred to as Jane Doe #6, investigators said.

One week later, two additional sets of human remains were found in Nassau County, about 40 miles east of New York City, one of which was identified as the mother of the toddler through DNA analysis. The mother’s partial remains were first discovered in 1997, officials said.

The other set of remains “genetically matched” with remains found in 1996 on Fire Island, “significantly expanding the timeline and geographic reach” of the investigation, officials said.

In mid-April of the same year, Steve Cohen, an attorney for Barthelemy’s mother, said a man using the victim’s cell phone made taunting calls and claimed he killed Barthelemy, CNN reported.

“Do you think you’ll ever see her again?” the unidentified male caller asked Barthelemy’s sister on August 26, 2009, according to Cohen.

“You won’t. I killed her,” he added and hung up. The phone call ended after less than a minute, CNN reported at the time.

Another phone call was placed in July 2009 just days after Barthelemy disappeared. It was the first of seven calls he made from Barthelemy’s cell phone. Cohen said in the phone call, the unidentified male caller referred to Barthelemy as a “whore” in a short conversation with her then-15-year-old sister, Cohen told CNN at the time.

In the final call, the man described in graphic detail to the victim’s sister what he had done sexually to Barthelemy, Cohen said.

In December 2011, Gilbert’s body was found in the wooded marshes of Suffolk County’s Oak Beach. The beach is about 9 miles from where the 10 other sets of human remains were found.

Authorities later said they believed Gilbert’s death may have been accidental and not related to the Gilgo Beach slayings.

2020: Police release photos of a key clue and ID a victim

In January 2020, Suffolk County police released photos of what it said could be a significant piece of evidence: a black leather belt embossed with the letters “WH” or “HM.” The department also launched a website to collect new tips in the investigation.

“We believe the belt was handled by the suspect and did not belong to any of the victims,” former Suffolk County Police Commissioner Geraldine Hart told reporters at the time.

On May 28, 2020, New York’s Suffolk County Police Department identified “Jane Doe #6” as Valerie Mack, a 24-year-old Philadelphia mother who went missing two decades earlier.

The FBI helped identify Mack’s remains using advanced forensic DNA technology, officials said.

Using samples from her remains, Suffolk County investigators were able to find Mack’s biological relatives through genetic genealogy, which ultimately led to her adoptive family and son, Hart said to reporters at the time.

2022: Police form task force to find killer

In February 2022, Suffolk County Police Commissioner Rodney Harrison formed a multiagency task force to investigate the Gilgo Beach killings.

The task force included the Suffolk County Police Department, the Suffolk County Sheriff’s Office, the New York State Police and the FBI.

On March 14, 2022, Heuermann was first mentioned as a possible suspect in the Gilgo Beach murder case after a New York state investigator identified him in a database, according to Suffolk County District Attorney Ray Tierney.

Investigators then started surveilling him and his family and took pieces of garbage – even discarded pizza crust – to obtain DNA samples.

As they closed in on Heuermann, investigators used cell tower records from thousands of possible individuals to narrow it down to hundreds and then to a handful of people. Next, authorities focused on residents who also matched a physical description provided by a witness who had seen the suspected killer.

Authorities zeroed in on anyone with a connection to a green pickup truck a witness had seen the suspect driving, according to two law enforcement sources with knowledge of the case. Later, authorities learned Heuermann drove a green pickup truck registered to his brother, CNN reported.

Heuermann matched a witness’s physical description, lived close to the Long Island cell site and worked near the New York City cell sites where other calls were captured.

Personal cell phone and credit card billing records revealed numerous instances where Heuermann was in the general locations as burner phones, which authorities say he had with him at the killings. He used the phones to call the three victims and also used “Brainard-Barnes and Barthelemy’s cellphones when they were used to check voicemail and make taunting phone calls after the women disappeared,” Suffolk County prosecutors allege.

Authorities said a search of Heuermann’s computer revealed he had scoured the internet at least 200 times for details about the status of the investigation, Tierney said. Heuermann was also compulsively searching for photos of the victims and their relatives, and he was trying to track down relatives, the district attorney said.

In late 2022, detectives recovered a cup believed to have been discarded by Heuermann, but they could not get a good DNA sample from it, a law enforcement source close to the investigation told CNN.

2023: Rex Heuermann arrested in some of the killings

In January 2023, investigators got a complete sample of Heuermann’s DNA from leftover crust in a pizza box he threw in the trash, a law enforcement source close to the investigation told CNN.

During the initial examination of one of the victims’ skeletal remains and materials discovered in the grave, the Suffolk County Crime Laboratory recovered a male hair from the “bottom of the burlap” the killer used to wrap her body, according to prosecutors. Analysis of the DNA found on the victim and the pizza thrown out by Heuermann showed the samples matched.

Additionally, hair believed to be from Heuermann’s wife was found on or near three of the murder victims, prosecutors allege in the bail application, citing DNA testing. The DNA came from 11 bottles inside a garbage can outside the Heuermann home, the court document says.

On July 13, 2023, a suspect connected to some of the Gilgo Beach murders was taken into custody in New York City, marking the first arrest in the case, according to Harrison. He was transported back to Suffolk County Police headquarters in the hamlet of Yaphank on Long Island, the police commissioner said.

A day later, authorities identified the suspect as Heuermann, a registered architect who has owned the New York City-based architecture and consulting firm RH Consultants & Associates since 1994, according to his company’s website.

The case against Heuermann came together over two years with the restart of the investigation, in which investigators used “the power of the grand jury,” including more than 300 subpoenas and search warrants, to collect evidence and tie Heuermann conclusively to the killings, Tierney said during a news conference.

2024: Charged in 6 deaths over 3 decades

Heuermann was indicted on two new murder charges in June, in connection with the deaths of Costilla and Taylor. He pleaded not guilty.

Taylor’s remains were discovered in Manorville in 2003 and then additional remains along Ocean Parkway on Gilgo Beach in 2011.

A hair found underneath Taylor’s remains was linked to Heuermann, according to the bail application.

Costilla’s remains were found in North Sea in 1993 by two hunters who were in the woods, according to the bail application.

“Defendant Heuermann is the individual who murdered, stripped, restrained, and transported the remains of Jessica Taylor and Sandra Costilla, as well as the Gilgo Four, until they were each discovered in 1993, 2003, 2010, and 2011,” the bail application read.

In September, Tierney announced prosecutors were seeking the public’s help in identifying a separate victim found in 2011 along the same stretch of Ocean Parkway as Waterman and Taylor.

The victim whom investigators are referring to as “Asian Doe” was a biological male of Asian descent, between the ages of 17 to 23, found wearing women’s clothing. Authorities said they believe the victim died in 2006 or earlier from blunt force trauma.

Tierney did not say whether the victim was connected to the investigation into Heuermann.