Investigators use DNA, genetic genealogy to ID another victim of Long Island serial murders

LONG ISLAND, N.Y. — Police on Long Island have added another link in a chain of 11 unsolved Gilgo Beach killings believed to be the work of a serial killer.

Using genetic genealogy, Suffolk County police investigators have identified one of the slain women, initially dubbed “Jane Doe No. 6,” as Valerie Mack, police officials said Thursday. Mack’s identification comes 20 years after she vanished.

Mack, a Craigslist escort who lived and worked in Philadelphia, was 24 years old when she was last seen in the spring or summer of 2000 in the area of Port Republic, New Jersey. Her partial remains were found in Manorville that November and near Cedar Beach in 2011.

Mack was never reported missing, Suffolk County Police Commissioner Geraldine Hart said in a video statement.

“It is our hope that our efforts bring some sense of closure and peace to Valerie’s family,” Hart said.

Watch the entire video statement here.

Police officials called Mack’s identification a “giant leap forward in the investigation.”

“Valerie Mack’s identification represents progress in this investigation, but there is much work left to do,” Hart said. “As detectives continue to relentlessly pursue leads related to her murder, we ask members of the public, friends, family, and associates of Valerie Mack to provide whatever information they have about her and the circumstances which may have led to her death.”

Mack was among 11 victims whose remains were found scattered along a stretch of beach on Long Island. The gruesome discovery was made as authorities searched for Shannan Gilbert, a 24-year-old Craigslist escort who vanished May 1, 2010, after running from a client’s home in the Oak Beach community.

Gilbert’s remains were ultimately found Dec. 13, 2011, in a marsh in Oak Beach.

Hart said her agency worked with the FBI and utilized advances in DNA technology, particularly genetic genealogy, to narrow down an identity for “Jane Doe No. 6,” as well as the two remaining unidentified Suffolk County victims.

A genealogy profile was established for Jane Doe and homicide detectives and federal agents used data from that profile to seek leads in areas of New Jersey to which she may have had ties.

They spoke to potential relatives of the victim and obtained DNA samples, which ultimately led to Mack’s identification.

“Our goal was, and continues to be, bringing justice to the victims and to their families,” Hart said.

Chilling discoveries

The chilling discoveries began with the disappearance of Gilbert.

“During the months that followed her disappearance, canine officers incorporated training exercises into searches of the area surrounding Gilbert’s last known location,” officials said on, a site devoted to the unsolved murders. “During one exercise, on Dec. 11, 2010, a set of skeletal remains was discovered in an area near Gilgo Beach off Ocean Parkway.

“The remains located would later be identified as Melissa Barthelemy.”

Two days later, the remains of three more Craigslist escorts were found nearby, spaced about 500 feet apart from one another, according to police. Those women were subsequently identified as Maureen Brainard-Barnes, Megan Waterman and Amber Lynn Costello.

All four women were reported missing between July 2007 and September 2010. Brainard-Barnes, 25, had last been seen in New York City in June 2007 and Barthelemy, 24, had been reported missing in July 2009 in the Bronx.

Waterman, 22, had last been seen in early June 2010 at a Holiday Inn Express in Hauppauge, New York, and Costello, 27, had vanished after leaving her North Babylon home in early September 2010, authorities said.

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A fifth set of partial remains belonging to Jessica Taylor were found several miles east of where the first four women, designated the “Gilgo Four,” were found. Suffolk County officials said some of Taylor’s remains had been found nearly eight years earlier in Manorville, in a wooded area on the northwest corner of Halsey Manor Road and the Long Island Expressway.

“The female’s head and hands were severed and missing,” authorities said. “Additional remains of Taylor were discovered on March 29, 2011, along Ocean Parkway during the search for Shannan Gilbert.”

Three more sets of remains – including those of Mack – were found April 4, 2011, during the Gilbert search.

Like those of Taylor, Mack’s remains were partial. Part of her body had been found by hunters in a wooded area off Halsey Manor Road in November 2000, three years before the majority of Taylor’s remains were found in the same area.

Searchers who found Mack’s remains in April 2011 also found the remains of an unidentified toddler nearby, as well as those of an unidentified Asian man.

Investigators hope that genetic genealogy can help solve their identities, as well.

“One week later, while searching further west along Ocean Parkway in Nassau County, two additional sets of skeletonized remains were found approximately 7 miles away from the discovery on April 4,” police officials said. “One set is believed to be the mother of the toddler found a week earlier. The other set of partial remains was linked through DNA analysis to remains found in Davis Park on Fire Island in 1996.”

All 11 murders remain unsolved. NBC News reported in January that Hart said Gilbert’s killing did not fit the pattern of the other 10 but that investigators were not ruling out the possibility that all the victims were killed by the same person.