Heuermann pleaded not responsible on Tuesday to Mack’s homicide in Suffolk County court docket.

The cost comes after Heuermann was initially arrested in 2023 and charged with the murders of Amber Lynn Costello, Melissa Barthelemy, and Megan Waterman. Earlier this yr, he was additionally charged with the murders of Maureen Brainard-Barnes, Jessica Taylor and Sandra Costilla.

He was linked to Mack’s homicide through forensic proof — together with a hair close to her physique allegedly matching the DNA of his spouse and daughter. Per prosecutors, the style of Mack’s loss of life and dismemberment additionally matched a “planning doc” discovered on Heuermann’s units.

A superseding indictment launched Tuesday provides extra perception into the continuing investigation and its findings — together with the invention of what prosecutors name “mementos” and “souvenirs” at Heuermann’s house and workplace following a search.

Inside a cardboard field in his Manhattan workplace, Gilgo Murder Process Drive brokers discovered a PEOPLE journal from November 7, 2016 with the headline “‘BODIES ON THE BEACH: HUNT FOR THE LONG ISLAND SERIAL KILLER: Who’s the cold-blooded assassin killing girls and dumping their our bodies on a New York Seashore?” on the duvet.

In his house, additionally they found a New York journal from 2011 with a “Serial Killer on Lengthy Island” cowl story.

Whereas these two clippings had been each present in 2023, a Might 2024 search of his house turned up newspapers inside his major bed room — together with a New York Put up with an article entitled, “Serial Killer Eyed in L.I. Slay.” The article, per prosecutors, included particulars on each Mack and Taylor’s disappearances.

Papers within the basement, in the meantime, included a 1993 article entitled “Physique Found in Woods,” which referenced Costilla’s murder investigation. All of the papers had been believed to have been store-bought and never subscriptions.

“Primarily based on the totality of the investigation, the Process Drive believes Rex A. Heuermann sought, bought, and stored these publications as, inter alia, ‘souvenirs’ or ‘mementos’ of his crimes, serving as a reminder of the occasions that occurred all through the murders of every sufferer,” famous prosecutors within the docs.

Stays had been first found in November 2000, when hunters got here throughout a plastic bag wrapped with duct tape. Contained in the bag, police found a torso, legs and arms; the sufferer’s head and fingers had been severed from her physique, whereas her proper leg had additionally been reduce off mid-calf.

She grew to become often called Jane Doe #6; her head, fingers and proper foot weren’t discovered for 11 years. In 2020, utilizing DNA samples from her stays, she was recognized as Mack, who authorities consider was a intercourse employee in each Philadelphia, Pennsylvania and Atlantic Metropolis, New Jersey.

Per the docs, she was additionally “identified to ‘road stroll,’ i.e., wander the streets in search of intercourse work.”

The Suffolk County Medical Examiner’s Workplace later decided she was killed between September 1, 2000 and November 19, 2000. The Medical Examiner’s Workplace additionally found accidents to the sufferer’s breast, which the docs observe had been “seemingly the results of autopsy mutilation of the sufferer’s breast with a pointy object.”

Through the examination, a human hair was additionally found by the victims left wrist, contained in the sealed rubbish baggage.

The hair allegedly got here up as a match for each Asa Ellerup and Victoria Heuermann, Heuermann’s spouse and daughter. Further forensic testing additionally allegedly confirmed the hair “is considerably extra prone to have derived from an individual genetically similar to Victoria Heuermann’s DNA profile, thereby linking proof from one more crime scene to the Defendant by way of his instant household.”

Victoria would have been between 3 and 4-years-old on the time.

Within the docs, prosecutors reiterated among the findings after executing search warrants on Heuermann’s digital units — this time linking them to Mack’s homicide as effectively.

“As beforehand detailed, an evaluation of those units has revealed Heuermann’s vital assortment of violent, bondage, and torture pornography, at the moment relationship again to 1994,” they wrote. “Furthermore, within the months main as much as Ms. Mack’s disappearance and homicide, the Process Drive uncovered pornographic pictures accessed by Heuermann which embody, breast mutilation, and the tying up of ladies with rope, which largely coincide with a.) the accidents inflicted on Ms. Mack’s breast and b.) how the rope ligatures had been utilized on Valerie Mack.”

Additionally they famous that through the month of September 2000, “investigators noticed a big uptick in downloads of pornographic pictures depicting Bondage, Self-discipline, Sadism, and Masochism.”

See how his lawyer beforehand defended Heuermann’s web exercise right here.

Prosecutors later identified elevated web makes use of of GilgoNews.com, which adopted the homicide investigation, within the days main as much as Mack’s id being revealed in 2020.

The docs additionally resurfaced particulars from a Phrase Doc investigators consider “to be a ‘planning doc’ utilized by Heuermann to methodically blueprint and ‘plan out’ his “kills.” Prosecutors identified that the unique doc “seems to have been created within the yr 2000, which notably coincides with the yr Valerie Mack was murdered.”

Investigators consider the “planning” doc “substantively pertains to the Mack investigation in different respects,” stating how they consider it advises for “small” victims and using dump websites, “ROPE/CORD,” “BAGS/TAPE” and “SAW/CUTTING TOOLS.” The doc additionally suggests to “REMOVE HEAD AND HANDS” AND “REMOVE ID MARKS [TATTOOS…”

Mack, in line with the Gilgo Murder Process Drive’s investigation, allegedly had a tattoo of her son’s title on her foot/ankle.

“The examination of the sufferer’s physique in 2000 revealed no tattoos on the sufferer’s left foot/ankle,” they wrote. “Primarily based on the foregoing, the Gilgo Murder Process Drive members consider the Defendant amputated Ms. Mack’s decrease proper leg on the mid-calf to inhibit and/or delay the identification of Ms. Mack’s tattoo and subsequently, Ms. Mack.”

Summing up the case, prosecutors wrote:

Primarily based on the foregoing, Rex A. Heuermann is now charged with the murders of seven victims. Of observe, two impartial laboratories have forensically linked proof from six of seven crime scenes to Defendant Heuermann and/or members of his instant household, or people with whom Heuermann resided.

Second, the HK Planning Doc’s creation in 2000, the identical yr Valerie Mack was murdered, in addition to its description of DS-1, or the primary “dump web site” as Mill Street, which is the place the stays of Ms. Mack had been found, additional emphasizes the doc’s relevance to the Valerie Mack murder investigation.

Moreover, the dismemberment of Ms. Mack’s proper leg, the place she had a tattoo of her son’s title, was clearly supposed to inhibit the identification of Ms. Mack, which is corroborated by the HK Planning Doc, its presence on Heuermann’s laptop computer pc, and the mutilation of Jessica Taylor’s tattoo similarly.

Lastly, the Gilgo Murder Process Drive members consider that Rex A. Heuermann’s possession of quite a few publications referring to not solely the “Gilgo 4,” but additionally Sandra Costilla, Valerie Mack, and Jessica Taylor, signifies the Defendant’’ makes an attempt to remind himself of the occasions that occurred all through the murders of every sufferer, revealing Rex A. Heuermann’s utter lack of disregard or regret for his actions, or the victims.