RIVERHEAD, Long Island (WABC) — Suspected Gilgo Beach serial killer Rex Heuermann has been charged in the death of a seventh woman.

Heuermann is charged with second-degree murder in connection with the killing of Valerie Mack, according to a superseding indictment released Tuesday.

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 in New Jersey this year.

On November 19, 2000, a hunter’s dog discovered some of Mack’s remains in a wooded area of ​​Manorville. 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.

Heuermann pleaded not guilty to killing Mack.

“Your honor, I am not guilty of any of these charges,” Heuermann said.

He appeared to be shackled in a suit and stood before the judge for just a few moments. Judge Timothy Mazzei continued to hold Heuermann without bail.

The defense has been given 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. The defense is also considering whether to ask the judge to separate the murder charge from others.

Prosecutors said they linked 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.

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 tying women with ropes, two things prosecutors say are consistent with the injuries to Mack’s chest and the way she was tied.

Investigators said they found a document they believe Heumerann used to “plan” 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.

The Suffolk County District Attorney’s Office was expected to hold a news conference along with local and state law enforcement following the court appearance.

Heuermann is accused of killing six other women whose remains were found on Long Island.

The investigation into the Gilgo Beach murders dates back to 2010, when police searching for a missing woman found 10 human remains in brush along an offshore island park path, sparking 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, they linked them to remains found years earlier elsewhere on Long Island. Police also began re-investigating other unsolved murders of women found dead on Long Island.

The case spanned five police commissioners, more than 1,000 tips and doubts as to whether there was even a serial killer.

Heuermann, who lived in Massapequa Park on Long Island with his wife and two children and commuted to an architectural firm in Manhattan, was arrested on July 13, 2023 and charged with the murders of Amber Lynn Costello, Megan Waterman and Melissa Barthelemy. He was charged with the murders of three other women – Maureen Brainard-Barnes, Sandra Costilla and Jessica Taylor – earlier this year. He pleaded not guilty to all charges.

ALSO READ: Gilgo Beach murders: Complete timeline of events leading to Rex Heuermann’s arrest

Prosecutors said in a superseding indictment court filing Tuesday that Heuermann kept newspaper and magazine clippings about the Gilgo Beach serial killings.

According to the filing, the items were found during searches of Heuermann’s dilapidated home in Massapequa Park.

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.

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Some information from ABC News and Associated Press

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