Long Island Serial Killer Suspect Charged With Two More Murders

The man accused of being the Long Island Serial Killer was charged with two more counts of murder in connection to the remains of victims found near his alleged dumping ground of Gilgo Beach and further east along Long Island’s southern coast.

According to a new Suffolk County bail application obtained by Rolling Stone, Long Island, Rex Heuermann — who already faces four murder cases in connection to “the Gilgo Four” victims — was charged in the cold-case murders of Jessica Taylor and Sandra Costilla, two more women whose remains were found near Manorville, Long Island, and Gilgo Beach and whose deaths predate the previous LISK victims by decades.

At least 10 bodies were discovered buried on the coast of Long Island’s Gilgo Beach in Dec. 2010. Police initially believed the corpses of four women found in close proximity to each other, each wrapped in similar burlap, were killed by the same person. Maureen Brainard-Barnes, Melissa Barthelemy, Megan Waterman, and Amber Costello, all of whom were sex workers at the time of their deaths, were dubbed “The Gilgo Four” and remained cold case victims of the Long Island Serial Killer until Heuermann’s arrest in July 2023. 

Heuermann — who was first charged with the murders of Barthelemy, Waterman, and Costello in July 2023 and Brainard-Barnes in January 2024 — has pleaded not guilty to all counts.

Like the previous four victims attributed to LISK, Taylor was a sex worker at the time of her disappearance in 2003. Her partial remains were first discovered near Manorville in 2003, with the rest of Taylor’s remains found in 2011 as part of a search that uncovered the 10 bodies in the vicinity of Gilgo Beach. 

“Investigators believe the mutilation of the victim’s tattoo, decapitation of her head, and dismemberment of Ms. Taylor’s arms, were acts perpetrated by Rex A. Heuermann to inhibit the identification of the victim via facial recognition, fingerprints and/or tattoo identification,” the bail application Thursday stated. “During the initial investigation in Manorville in 2003, the victim’s head, arms, and hands were not found at the scene and their location remained unknown to law enforcement for approximately eight years.”

As with the previous cases, it was DNA evidence that ultimately tied Heuermann to his victims: Male hair recovered from the bodies of Costilla and Taylor excluded “99.96% of North American population but not Rex Heuermann,” the bail application notes. In the case of Costilla, additional mitochondrial DNA found on her remains was connected to an unnamed woman (called “Witness 3”) who Heuermann was living with at the time of Costilla’s 1993 disappearance.

Heuermann, potentially, could face even more murder charges: Following the discovery of Taylor’s remains, investigators long believed that she and Valerie Mack — another sex worker who disappeared in 2003 and whose remains were found as part of the LISK search in 2011 — were the victims of the same killer, as their remains were disposed of in a similar manner in the same area near Manorville. While Heuermann was not charged with the murder of Mack Thursday, the bail application mentions Mack several times and notes the similarities between her 2000 murder and Taylor’s in 2003.

The Costilla murder had been a cold case since 1993, when her remains were found in Southhampton, far east of the Gilgo Beach dumping ground.

Incidentally, Manorville was the home of another convicted serial killer, John Bittrolff, a one-time LISK suspect who was also eyed in the death of Taylor and Mack due to the remains’ proximity to Manorville and the fact he was also convicted of killing two sex workers. Costilla was also long believed to be a victim of Bittrolff’s until Heuermann was charged with her murder Thursday.

“On or about August 1, 2014, Forensic Laboratory # 2 received an extract of John Bittrolff’s buccal swab. Forensic Laboratory 2 was then able to develop a mitochondrial DNA profile from John Bittrolff’s buccal swab and subsequently compared it to the mitochondrial DNA profiles that had been previously generated for each of the Hairs on Costilla. At the conclusion of its analysis, Forensic Laboratory # 2 was
able to exclude John Bittrolff, and his maternal relatives, as contributors of the Hairs on Costilla,” the bail application notes.

Following Heuermann’s arrest, however, the DNA recovered from Costilla’s body was tested against his. “Based on the foregoing, while 99.96% of the North American population can be excluded as the contributor of the Male Hair on Costilla, Defendant Heuermann cannot be excluded as the contributor of the Male Hair on Costilla,” the bail application said.

While the Costilla case is built entirely around DNA, investigators laid out more evidence in connection to Taylor’s 2003 murder. “At the time of Ms. Taylor’s disappearance, Rex A. Heuermann worked in the same vicinity as where Ms. Taylor was known to ‘street walk,’ i.e., work as a sex worker. Records seized during
the execution of prior search warrants reveal Heuermann was, in fact, present in Midtown Manhattan
on July 21, 2003, the same date Ms. Taylor disappeared.”

As with the “Gilgo Four” murders, Heuermann’s family was out of town and on vacation at the time of Taylor’s disappearance and murder, witnesses told investigators. Additionally, a digital forensic search of Heuermann’s computers found that in 2003, Heuermann “accessed a Newsday Article entitled, ‘Cops Seek Help in IDing Manorville Body,’ regarding the discovery of Ms. Taylor’s human remains,” and then attempted to delete that online activity.

The bail application also revealed the chilling “digital evidence” found on computer devices obtained in the searches of Heuermann’s Massapequa home.

“An analysis of these devices has revealed Heuermann’s significant collection of violent, bondage, and torture pornography, currently dating back to 1994. The pornographic images accessed by Heuermann include, but are not limited to, breast mutilation, vaginal torture, sex substitution (i.e., penetration with an object), the sexualization of decapitated women, bondage, and whipping, which notably and largely coincide with how the remains of Sandra Costilla, Jessica Taylor, and Valerie Mack were discovered.”

A search of an external hard drive found in Heuermann’s basement uncovered “HK Planning Document,” a text file that essentially reads as a do’s and don’ts for a serial killer, complete with a checklist of necessary items (tarps, police scanner, “rope / cord,” hair nets, etc.) as well as a list of potential dump sites.

The bail application notes that Taylor and Mack’s partial remains were found near two of the listed dump sites, and given the HK Planning Document was repeatedly accessed between 2000 and 2004, investigators believe the document was used specifically to prepare for the Taylor (and Mack, if charged) murders. (At a press conference Thursday, in regards to charges related to Mack’s murder, Suffolk County District Attorney Ray Tierney said, “We’re gonna continue to investigate.”)

Another section in the HK Planning Document, called “BODY PREP, includes “a note to ‘REMOVE HEAD AND HANDS,’ which clearly relates to the condition of Jessica Taylor’s and Valerie Mack’s remains, as both victims were decapitated and dismembered at their arms below their elbows. Additionally, each of these victim’s remains, as well as the remains of the ‘Gilgo Four’ were indeed ‘packaged for transport,’ as this section indicates to do, further increasing the significance of this document’s presence on Heuermann’s laptop computer. Finally, this section also includes a note to ‘REMOVE ID MARKS [TATOOS][sic],’” the bail application states.

“The examination of Ms. Taylor’s body in July 2003 indicated numerous sharp ‘linear injuries’ to the victim’s skin, specifically around where Ms. Taylor’s tattoo had been located, which investigators believe was intended to inhibit the identification of Ms. Taylor’s tattoo and therefore, Ms. Taylor, in a manner consistent with the HK Planning Document.”

The document also included reconnaissance on surveillance cameras in the areas of the dump sites, heavily cited the true crime book Mind Hunter written by an FBI serial killer profiler, and doled out advice like “REMEMBER DON’T CHARGE GAS” and “THE MORE YOU DO THE MORE CLUES YOU GIVE.”

“The Gilgo Homicide Task Force members believe that the totality of circumstances surrounding the HK Planning Document, including Heuermann’s attempt to delete its existence, points to it as Heuermann’s self-education and ‘homework’ on the topic of carrying out serial, sexual murder,” the bail application stated.

At a press conference following Heuermann’s additional murder charges, Suffolk County District Attorney Ray Tierney said the planning documents – found among a trove of hundreds of laptops, external hard drives, SIM cards, digital cameras, tablets, cell phones, and more removed from Heuermann’s home – prove that Heuermann’s “intent was nothing short but to murder these victims.”

Additionally, the planning documents were “identical in methodology” to how the six victims so far attributed to LISK were murdered,” Tierney said. “We said the case was not over. We said we would expand the cases, from Gilgo and off. And we’ve done that… We are not going to stop. This case continues.”