Cover photo: D.A. Tierney announces developments in the Gilgo Beach case in Riverhead on Tuesday morning (Credit – Matt Meduri)
The famous cold case that rocked the nation decades ago continues to develop.
Defendant Rex Heuermann (pictured below) is now being charged with second-degree murder for the death of Valerie Mack, the seventh murder allegation he faces in the mounting case against him regarding the Gilgo Beach serial killings.
To date, Heuermann has been charged with the deaths of several other victims, including the “Gilgo Four,” the original four victims found along Gilgo Beach in 2010. In July 2023, District Attorney Ray Tierney (R) made the stunning announcement that, at long last, a suspect had been identified. At that time, Tierney unveiled the first- and second-degree murder charges in relation to Melissa Barthelemy, Megan Waterman, and Amber Lynn Costello.
The “Gilgo Four” charges were complete with a January 16, 2024, super-seding indictment that alleges Heuermann is responsible for the death of Maureen Brainard-Barnes.
On June 6, 2024, Tierney once again announced more charges, now eclipsing the original scope of the “Gilgo Four” and branching out now to remains found in Manorville. He was charged with second-degree murder in relation to both Jessica Taylor and Sandra Costilla. The June indictment was especially revealing in the case, as it demonstrated Heuermann’s seemingly innocuous whereabouts at a sport rifle range just around the corner from where he would leave the remains of Melissa Taylor. It also opened up the possibility of his connections to the outstanding ten other potential victims related to the Gilgo Beach murder spree that is assumed to have taken place from 1993 until 2011, as well as to locations far removed from the western end of Suffolk. The remains of Sandra Costilla were found in North Sea, a hamlet in the Town of Southampton that borders the Peconic Bay.
Now, on December 17, 2024, Rex Heuermann faces a second-degree murder charge in the death of Valerie Mack.
On or about November 19, 2000, three individuals with a hunting dog were combing the woods of Manorville, only to stumble upon a black plastic bag wrapped with duct tape. The remains were found about one mile west of Halsey Manor Road and north of Mill Road. Inside the bag, the hunters found additional black bags and a decapitated human, later identified to be Mack.
Both of Mack’s hands had been severed from her body above the wrists, while her right leg had also been amputated at the mid-calf. However, her head, hands, and right foot were conspicuously absent from the bag in Manorville and would not be discovered by authorities for another eleven years.
On April 4, 2011, during an expanded search of the Gilgo Beach area, Mack’s skull, hands, and right foot were discovered along Ocean Parkway, less than 1.5 miles from where Jessica Taylor’s skull, hands, and forearm were discovered. Mack’s remains were discovered on the same side of the road and at a similar depth within fifty feet from the edge of the parkway, positing that any suspect would likely be tied to both victims.
For years, Mack was referred to by detectives as “Jane Doe #6,” but only until a May 28, 2020, DNA report successfully identified her as Valeric Mack.
Born June 2, 1976, in Atlantic City, Mack was born Valerie Lyn Fulton. After years of being shuffled through the foster system, she was adopted by the Mack family. In 1994, Mack, aged 17, gave birth to a son and lived with her son’s father in Wildwood, New Jersey. However, in 1996, Mack had her first run-in with the law in Philadelphia, working as a prostitute, advertising online and conducting “street walks.”
Joanne and Edwin Mack, parents of Valerie, were present, but did not speak before the press.
“The family are extraordinary people and we are honored to prosecute this case for Valerie and her family,” said D.A. Tierney, joined by the families of the victims who have previously been tied to Heuermann. “I think the Mack family is emblematic of other families in this case, who have steadfastly stood by their loved ones and jealously guarded their memories, and we have nothing but respect and admiration for those victims’ families.”
Tierney touted the mitochondrial DNA evidence that has been utilized to identify a possible suspect in Heuermann, while also ruling out the defendant’s wife and daughter. He also mentioned the document found on Heuermann’s computer in a summer raid of the Massapequa Park home, which also produced a litany of devices, hard drives, tapes, and other paraphernalia. The document, referred to as the “HK Document,” allegedly contains Heuermann’s modus operandi for the murders, as well as his seemingly deliberate attempts to cover his tracks and get in the mind of a detective.
However, the HK Document coincides with the state in which the Heuermann home was found by authorities, according to Tierney and the Gilgo Beach Task Force. It leaves the door of possibility open for murders to have been committed in the home, only for Heuermann to have allegedly scattered the remains across Suffolk County.
“If you look at the planning [HK] document and if you look at the adhesive staining on the walls and decomposed tile, certainly all of that is consistent with the commission of those murders,” said Tierney, noting that, as of now, there is no specific evidence showing that Mack was killed in the home while Heuermann’s wife and daughter were away, a detail consistent with the other murders tied to Heuermann so far.
Meanwhile, the defense continues to raise questions about the use of the cutting-edge DNA evidence, claiming the technology is too new and has never been used in New York State to aid a prosecution, while also only having been used a “handful of times” in other countries in a similar fashion. Tierney said he anticipates those challenges to culminate in a specific hearing about what kinds of evidence are on the table for this investigation, with a judge signing off on the admissibility of the evidence in court.
However, Tierney remains confident that even if the DNA evidence is deemed inadmissible, the prosecution still has plenty of evidence with which to build a case.
“We have the phone records, the financial records, the Internet searches, and the various things that he has kept since 1993,” said Tierney. “All the evidence contains a certain picture, and the picture will need to prove itself.”
Moreover, old newspapers and magazines with articles about the Gilgo Beach murders and ensuing investigation were found in the home, which prosecutors allege Heuermann kept as “souvenirs” or “mementos” from his spree. One obtained was a July 29, 2003, copy of The New York Post that discussed the investigation in Mack and Taylor.
“I scored a touchdown in high school. I still have that article,” Tierney quipped, yet with a tone of seriousness that relays the massive case his team has been building since last July.
The prosecution believes that a hearing will be scheduled as early as February or as late as March regarding the admissibility of the DNA evidence, but that a trial could come sooner than expected as well.
As of now, Tierney and the Gilgo Beach Task Force cannot make certain how many more indictments, if any, would emerge before a trial commences. Tierney said that the “answer to the question” of when a trial will begin “changes on a daily basis,” depending on the evidence and witnesses the prosecution receives.
“We have an obligation to investigate these cases and provide closure to as many families as we can, and that’s whether or not this results in additional charges for anyone,” said Tierney. “