Who is Valerie Mack? Accused serial killer charged with murdering woman with ties to Philadelphia

PHILADELPHIA (WPVI) -- Rex Heuermann, the suspected Gilgo Beach serial killer, was officially charged on Tuesday in the murder of a New Jersey woman who was known to frequent and work in the Philadelphia area.

Heuermann pled not guilty to the seventh murder charge in connection with victims found along Long Island's Gilgo Beach.

The latest victim, identified as 24-year-old Valerie Mack, was a sex worker in the Philadelphia and Atlantic City areas, according to a superseding indictment that was unsealed on Tuesday.

During a court appearance on Tuesday, stunning details emerged about Mack, her murder and her alleged killer 24 years after her remains were found.

Here's what we know:

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. He has previously been charged with murdering Amber Lynn Costello, Megan Waterman and Melissa Barthelemy, Maureen Brainard-Barnes, Sandra Costilla and Jessica Taylor. He has pleaded not guilty to all charges.

On November 19, 2000, a hunter's dog discovered some of Mack's remains in a wooded area of Manorville, New York. The remains were in a black plastic bag wrapped with duct tape. The bag contained additional plastic bags that contained Mack's decapitated body.

"Moreover, both of her hands had been severed from her body, above the wrists, and the victim's right leg had also been cut off from her body at the mid-calf," according to a bail application that accompanied the new indictment. "Ms. Mack's torso, legs and arms were also bound with rope."

The rest of her remains were found more than a decade later, in April 2011, along Ocean Parkway near Gilgo Beach.

The Suffolk County Medical Examiner's Office said they were able to determine from the remains that the victim had been dead for about two-to-eight weeks before being discovered. The medical examiner's office was then able to narrow down the victim's death to on, about or between September 1, 2000 and November 19, 2000.

Until May 2020, Mack's remains had been known only as "Jane Doe #6" until she was finally identified through DNA.

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Mack, who was originally born in Atlantic City with the name "Valerie Kyn Fulton," was placed into foster care at an early age and shuffled around foster homes until she was ultimately adopted by the Mack family, according to the unsealed indictment.

Officials say Mack began living with her father's son in Wildwood, New Jersey in 1994 and began frequently traveling between the New Jersey and Philadelphia. Then, in 1996, she had her first contact with Pennsylvania law enforcement, resulting in the first of several prostitution-related arrests by Philadelphia police, according to court documents.

Police said Mack advertised her sex work online, primarily under the alias of "Melissa Taylor," but was also known to "street walk."

Prosecutors said they were able to link Heuermann to Mack's death in part through a mitochondrial DNA analysis of a female hair found on Mack's body. It matched the profiles of Heuermann's wife and daughter, the bail application said. At the time of Mack's murder, Heuermann's daughter would have been between 3 and 4 years old.

Officials have also been able to determine that hairs recovered on six of seven victims Heuermann has been charged with killing are forensically tied to him or immediate family members or other people he lived with. Prosecutors allege this further supports claims that Heuermann murdered and transported the remains of each victim.

Prosecutors said they also linked Heuermann to Mack's death through evidence recovered on some of the 350 electronic devices they seized from him that include his "significant collection of violent, bondage and torture pornography" dating back to at least 1994.

This online collection included images of breast mutilation and tying up women with rope -- two things prosecutors said are consistent with injuries inflicted on Mack's breast and how she was bound.

ALSO SEE: 'Blueprint' of murders helps lead to Heuermann's charges in deaths of 2 more women: prosecutors

Investigators said they found one document that they believe Heuermann used to "plan out" his kills. The document was created in 2000, the year Mack was killed. Under a section entitled "supplies" Heuermann allegedly listed "rope/cord," "saw/cutting tools," "foam drain cleaner." Under a section labeled "DS," believed to stand for "dump site," Heuermann allegedly listed one of the locations where Mack's remains were found.

The document also included a "body prep" section with a note to "remove head and hands," according to the bail application. That relates to the condition of Mack's remains, prosecutors said.

Heuermann kept newspaper and magazine clippings about the Gilgo Beach serial killings, prosecutors also said Tuesday. They include a People coverage "Bodies on the Beach: Hunt for the Long Island Serial Killer" found in a cardboard box shortly after Heuermann's arrest in 2023.

In a more recent search, May 2024, prosecutors said they found a 2003 New York Post edition with an article entitled "Serial Killer Eyed in LI Slay" and a 1993 copy of Newsday with an article headlined "Body Discovered in Woods."

"Rex A. Heuermann sought, purchased and kept these publications as souvenirs or mementos of his crimes," prosecutors said.

During Tuesday's court appearance, the judge gave the defense until next month to file motions related to evidence. The defense has questioned the DNA methods prosecutors used and may try to limit admissibility at trial.

"They went through that house and that property with a fine tooth comb. They dug up the basement. They dug up the backyard. They went into the walls. They went into the pipe, they went under the foundation, and they have yet to show anyone any evidence," said defense attorney Michael Brown.

They are also considering whether to ask the judge to sever any of the murder charges from others, according to ABC News.

Heuermann continues to be held without bail.