Suspect in Gilgo Beach serial killings is charged in the death of a seventh woman

RIVERHEAD, N.Y. (AP) — The New York architect facing murder charges in a string of deaths known as the Gilgo Beach killings was charged on Tuesday in the death of a seventh woman.

See a full timeline of the investigation below and watch a portion of a press conference from Suffolk County District Attorney Ray Tierney in the video above

Rex Heuermann pleaded not guilty to killing Valerie Mack, whose remains were first found on Long Island in 2000. Mack, 24, had been working as an escort in Philadelphia and was last seen by her family that year in New Jersey.

Some of Mack’s skeletal remains were initially discovered in Manorville, New York; authorities found more of her remains about 50 miles (80 kilometers) west, in Gilgo Beach, more than 10 years later. They were unidentified until genetic testing revealed her identity in 2020.

Human hair found with Mack’s remains was sent for testing earlier this year and found to be a likely match with the genetic profile of Heuermann’s daughter, prosecutors said in court papers. His daughter is not accused of any wrongdoing and would have been 3 or 4 years old when Mack died.

Heuermann, 61, is charged with killing six other women whose remains were found on Long Island. He has pleaded not guilty to all the charges.

“The lives of these women matter. We, as investigators, understand that. No one understands that more than the families,” Suffolk County District Attorney Ray Tierney said at a news conference with Mack's parents and other victims' relatives.

The investigation into the Gilgo Beach killings dates back to 2010, when police searching for a missing woman found 10 sets of human remains in the scrub along a barrier island parkway, prompting fears of a serial killer.

Over the years, investigators used DNA analysis and other clues to identify the victims, many of whom were sex workers. In some cases, authorities connected them to remains found elsewhere on Long Island years earlier. Police also began reexamining other unsolved killings of women found dead on Long Island.

The case has dragged on through five police commissioners, more than 1,000 tips, and doubts about whether there was a serial killer at all.

Heuermann, who lived with his wife and two children in Massapequa Park on Long Island and commuted to a Manhattan architecture office, was arrested on July 13, 2023. At that point, he was charged with murdering Amber Lynn Costello, Megan Waterman and Melissa Barthelemy.

Earlier this year, he was charged in the deaths of three other women — Maureen Brainard-Barnes, Sandra Costilla and Jessica Taylor.

In a June court filing, prosecutors said they had recovered a file on a hard drive in Heuermann’s basement that he used to “methodically blueprint” his killings — including checklists with tasks to tick off before, during and afterward, as well as lessons for “next time.”

In court papers on Tuesday, prosecutors said the document, which was created the same year as Mack’s murder, includes details that align with her case.

For example, it names “Mill Road” — a road near where Mack’s first remains were found — under the heading “DS,” which investigators believe stands for “dump site.”

The document also lists “foam drain cleaner” under “Supplies.” Prosecutors say that on Oct. 3, 2000, Heuermann’s phone records appear to show him making two calls to a Long Island plumbing company, and he paid another company the following month to check his mainline drain.

In recent searches of Heuermann’s home and office, authorities say they found old magazines and newspapers with articles about the Gilgo Beach killings and investigation that prosecutors believe he kept as “souvenirs” or “mementos.” Among them was a July 29, 2003, copy of the New York Post that included an article about the disappearance and deaths of Mack and Taylor.

Prosecutors are also looking into the death of Karen Vergata, whose remains were first discovered in 1996 and finally identified in 2022 after a new DNA analysis.

In September, authorities released new renderings of an unidentified victim who was found in 2011. Officials said the victim, whom for years they had identified as male, may have presented outwardly as female and died in 2006.

Here is a timeline of the investigation:

Nov. 20, 1993: Two hunters discover the body of Sandra Costilla, 28, in a wooded area of North Sea, a hamlet in the Hamptons near the eastern end of Long Island. Costilla had been living in New York City.

April 20, 1996: The partial remains of Karen Vergata are discovered on Fire Island, a barrier beach off Long Island's southern coast. Her name remains unknown to investigators until 2022, when new DNA analysis helps them make an identification. Vergata, 34, was last in contact with her family on Feb. 14, 1996. She was involved in sex work when she vanished.

June 28, 1997: The partial remains of a woman, nicknamed “Peaches” by investigators after a tattoo on her body, are discovered stuffed inside a plastic tub in a state park in West Hempstead, New York. Her identity remains unknown.

September 2000: The partial skeletal remains of Valerie Mack, who had been working as an escort in Philadelphia, are found in a wooded area in Manorville, New York. Mack, 24, was last seen by her family in the spring or summer of that year in Port Republic, New Jersey.

July 26, 2003: The partial skeletal remains of Jessica Taylor are discovered in a wooded area of Manorville. She was 20 when she vanished and had been an escort working in New York City.

July 9, 2007: Maureen Brainard-Barnes, 25, who had traveled to New York City from her home in Norwich, Connecticut, for sex work, is last heard from by a friend. She says she is leaving her hotel to meet a client. Investigators later say cellphone records showed her phone was last used on Long Island.

July 10, 2009: Melissa Barthelemy, a 24-year-old sex worker, is last seen at her apartment in the Bronx. She tells a friend she is going to see a man and will be back in the morning. Cellphone location data puts her phone's last known location on Long Island. Days later, a man begins using Barthelemy’s mobile phone to make taunting phone calls to her relatives.

May 1, 2010: Shannan Gilbert, a sex worker, disappears in the barrier island community of Oak Beach, New York, after fleeing the house of a client and banging on a neighbor’s door. In a recorded 911 call, she tells a dispatcher that people are after her, but she can also be heard refusing offers of help. Her pimp, the client and his neighbor all tell police she appeared disoriented and ran into the night on her own.

June 6, 2010: Megan Waterman, 22, who had traveled to Long Island from Maine for sex work, is last seen at a motel in Hauppauge, New York.

Sept. 2, 2010: Amber Lynn Costello, 27, is last seen leaving her home in West Babylon to meet with a sex work client. A male friend later tells investigators he noticed a Chevrolet Avalanche, presumably driven by the client.

December 11, 2010: A police officer and his dog discover Barthelemy's remains while conducting a training exercise along Ocean Parkway.

Dec. 13, 2010: Police find the bodies of Costello, Brainard-Barnes and Waterman on the same quarter-mile stretch of Ocean Parkway where Barthelemy’s remains were located.

Dec. 14, 2010: Suffolk County Police Commissioner Richard Dormer publicly announces the discovery of the bodies and says a serial killer might be to blame. Police expand the search, looking for additional remains or any sign of Gilbert.

March 29, 2011: Some of Taylor’s remains are discovered along Ocean Parkway.

April 4, 2011: Additional remains of Valerie Mack are found along Ocean Parkway. Near those remains, investigators also find the remains of an unidentified female toddler, later identified through DNA as the daughter of “Peaches.” Elsewhere on the parkway, investigators discover the remains of an Asian male. Investigators estimate he died five to 10 years earlier and was in his late teens or early 20s. He still has not been identified.

April 11, 2011: Additional remains of Vergata are discovered along Ocean Parkway, several miles west of Gilgo Beach. Police also find remains belonging to “Peaches” along the beach parkway.

Dec. 13, 2011: Gilbert’s skeletal remains are discovered in a tidal marsh near Oak Beach. After an autopsy and further investigation, Suffolk Police say she most likely accidentally drowned. Her family still suspects she was slain.

January 2022: The Suffolk County district attorney convenes a new task force to investigate the Gilgo Beach killings.

July 13, 2023: Investigators arrest Heuermann and charge him with murdering Costello, Waterman and Barthelemy. The key evidence in the case is mobile phone location data suggesting that Heuermann and the women were in the same places at some of the same times, and traces of DNA found on the remains.

Jan. 16, 2024: Heuermann is charged in the death of Brainard-Barnes. Prosecutors say a hair found with her corpse is genetically similar to a DNA sample from Heuermann's wife.

Late April 2024: Police conduct a new, multiday search of a wooded area in Manorville where Taylor and Mack's remains were discovered more than a decade earlier. They also perform a new search on the spot where Costilla's body was discovered in 1993.

May 20, 2024: Investigators launch a new search of Heuermann's home. It lasts nearly a week.

June 6, 2024: Heuermann is charged with murdering Costilla and Taylor. He pleads not guilty.

Dec. 17, 2024: An indictment is unsealed charging Heuermann in Mack's death. Heuermann pleads not guilty.