Who is Valerie Mack? Accused Gilgo Beach serial killer Rex Heuermann is charged with the murder of a woman with ties to Philadelphia

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

Heuermann pleaded not guilty to a seventh murder charge related to victims found on Gilgo Beach on Long Island.

The youngest victim, 24-year-old Valerie Mack, was a sex worker in the Philadelphia and Atlantic City areas, according to a superseding indictment released Tuesday.

At a court hearing Tuesday, startling details emerged about Mack, her murder and her alleged killer 24 years after her remains were discovered.

Here’s what we know:

Heuermann, who lived with his wife and two children in Massapequa Park on Long Island and commuted to an architectural firm in Manhattan, was arrested on July 13, 2023. He was previously accused of murdering Amber Lynn Costello, Megan Waterman and Melissa Barthelemy, Maureen Brainard-Barnes, Sandra Costilla and Jessica Taylor. He 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. Inside the bag were more plastic bags containing Mack’s decapitated body.

“In addition, both of her hands had been severed from her body above the wrists and the victim’s right leg had also been severed from her body at mid-calf,” said a bail application attached to the new charge sheet. “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, off Ocean Parkway near Gilgo Beach.

The Suffolk County Coroner’s Office said it could determine from the remains that the victim had been dead for about two to eight weeks before he was discovered. The coroner was then able to narrow down the victim’s death to between September 1, 2000 and November 19, 2000.

Until May 2020, Mack’s remains were known only as “Jane Doe #6” until she was finally identified through DNA.

RELATED: Gilgo Beach Murders | Here is a timeline of the investigation

Mack, who was originally born in Atlantic City under the name “Valerie Kyn Fulton,” was placed in foster care at a young age and moved between foster homes until she was finally adopted by the Mack family, the unsealed indictment says.

According to officials, Mack had lived with her father’s son in Wildwood, New Jersey, since 1994 and traveled frequently between New Jersey and Philadelphia. Then, in 1996, she had her first contact with Pennsylvania law enforcement, which led to 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 “Melissa Taylor,” but was also known to “walk the streets.”

Prosecutors said they were able to link Heuermann to Mack’s death in part through 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 was probably between 3 and 4 years old.

Officials were also able to determine that hair recovered from six of the seven victims Heuermann was accused of killing was forensically linked to him or his immediate family members or other people with whom he lived. Prosecutors claim this further supports the claim that Heuermann murdered and transported each victim’s remains.

Prosecutors said they also linked Heuermann to Mack’s death through evidence recovered from some of the 350 electronic devices seized from him, including his “significant collection of violence, bondage and torture pornography,” which at least dating back to 1994.

That online collection included images of breast mutilation and women being bound with ropes – two things that prosecutors say are consistent with the injuries to Mack’s chest and the way she was bound.

SEE ALSO: ‘Blueprint’ of Morden leads to Heuermann’s indictment for murder of two more women: prosecutors

Investigators said they found a document that they believe shows Heuermann “planned” his killings. The document was created in 2000, the year Mack was killed. Under the “Consumables” section, Heuermann allegedly listed “rope/string,” “saw/cutting tools,” and “foam drain cleaners.” Under a section labeled “DS,” which presumably stands for “Dump Site,” Heuermann allegedly listed one of the locations where Mack’s remains were found.

The document also included a section on “body preparation” with a note to “remove the head and hands,” according to the bail application. That has to do with the condition of Mack’s remains, prosecutors said.

Prosecutors said Tuesday that Heuermann kept newspaper and magazine clippings about the Gilgo Beach serial killings. This includes a People report, “Bodies on the Beach: Hunt for the Long Island Serial Killer,” which was found in a cardboard box shortly after Heuermann’s arrest in 2023.

In a more recent search in May 2024, prosecutors said they found a 2003 edition of the New York Post with an article headlined “Serial Killer Eyed in LI Slay” and a 1993 edition of Newsday with the headline ” 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 hearing, the judge gave the defense until next month to file motions related to evidence. The defense has questioned prosecutors’ DNA methods and may seek to limit its admissibility in court.

According to ABC News, they are also considering whether to ask the judge to separate the murder charge from others.

Heuermann remains held without bail.