Prosecutors in the Suffolk County, New York, confirmed Thursday that the suspected Gilgo Beach serial killer has been formally accused of two more murders, but the bail application to make extra certain that Rex Heuermann remains behind bars also provided details that are chilling in their implications.
Heuermann, now 60, was infamously arrested last summer on the strength of discarded pizza crust and DNA evidence that allegedly linked him to male hairs found on the victims, of whom there are now six.
The Manhattan architect, already accused of murdering Melissa Barthelemy, 24, Megan Waterman, 22, Amber Costello, 27, and Maureen Brainard-Barnes, 25, in the late 2000s and 2010 on Long Island, has since been indicted in the 2003 slaying of Jessica Taylor, 20, and the 1993 murder of Sandra Costilla, 28.
(L-R): Maureen Brainard-Barnes, Melissa Barthelemy, Megan Waterman, Amber Lynn Costello, the women known as the “Gilgo Four” whose bodies were found on a remote Long Island beach in December 2021. They were last seen on dates between 2007 and 2010 and are believed to be the same victims of a serial killer. (Pictures via the Suffolk County (New York) Police Department.)
Simply put, the link between Heuermann and a murder from the early 1990s, when he would have been around 30 years old, raises the distinct possibility that, if he really is who prosecutors say he is, there’s no telling how far back the serial killings largely targeting sex workers may go or how many victims there might be.
Prosecutors in Suffolk County DA Raymond Tierney’s office described the slayings as “serious and heinous” in nature, as evidenced by the “planning and forethought that went into these crimes.”
Much of the bail application was spent detailing how investigators, who have searched Heuermann’s Massapequa Park home on numerous occasions, came to the conclusion that the defendant was responsible for two more murders that preceded that four he’s already suspected of committing.
Accused Gilgo Beach serial killer Rex Heuermann (left) appears in court after indictment in two more murders (Newsday/ James Carbone/pool), (right inset) Sandra Costilla and Jessica Taylor in family photos (Fox 5/screengrab)
Sandra Costilla was found dead on Nov. 20, 1993, by hunters in “in a wooded area of Southampton,” prosecutors said, noting that she suffered “numerous sharp force injuries” all over her body and was “lying on her back with her arms outstretched over her head with her uncovered legs spread apart.”
Investigators said that a male hair and a female hair, that of Witness 3 (a woman who lived with Heuermann but left two months before the murder), were found on Costilla’s remains.
Only in 2014 did authorities develop “unique mitochondrial DNA profiles for each of the Hairs,” and only in February 2024, well after Heuermann’s arrest, did forensic investigators conclude that the “profile developed from the Male Hair on Costilla and the profile developed from Defendant’s buccal swab are the same.”
Prosecutors said that both Witness 3 and Heuermann’s mother weren’t living at his home any longer at the time Costilla was murdered, supporting their theory that the defendant planned the serial killings in such a way as to ensure he had “unfettered time to execute his plans” and wouldn’t get caught, just like in the murders of Barthelemy, Waterman, Costello, and Brainard-Barnes.
More Law&Crime coverage: Accused Gilgo Beach serial killer’s search terms reveal penchant for sexual violence and cruelty, prosecutors say
In addition, the state claimed to have evidence that Heuermann had a “significant collection” of and an appetite for “violent, bondage, and torture pornography” depicting women, an alleged collection “currently dating back to 1994,” the year after Costilla’s horrific death.
The violent pornography, which the state says was uncovered due to the “seizure” and analysis of some “350 electronic devices” from the defendant’s residence, allegedly involved the “sexualization of decapitated women.”
Jessica Taylor was found “decapitated” with her “arms […] severed from her body below her elbows” in Manorville back in 2003. Like Costilla, Taylor’s remains were mutilated with a “sharp object,” prosecutors said. Authorities suspect that Heuermann also discarded Taylor’s limbs along the side of Ocean Parkway, remains that would not be found until 2011.
Among the startling evidence made public by the prosecution were details that Heuermann allegedly studied serial killers and wrote planning notes to himself on Microsoft Word inspired by Mindhunter: Inside the FBI’s Elite Serial Crime Unit, a “paperback book authored by [retired FBI Special Agent] John Douglas, specifically the First Edition published in 1996, concerning the criminal profiling of serial killers.”
Douglas is famous for his work with FBI’s Behavioral Analysis Unit — or the Behavioral Science Unit, as it was formerly known, which viewers of the dramatized Netflix series “Mindhunter” would be familiar with.
The Microsoft Word document, which prosecutors referred to as the “HK Planning Document” based on part of the file name, included notes that appeared to be lifted verbatim from the “Mindhunter” book and noted the corresponding page numbers. That, the stated alleged, explains why Heuermann tried but failed to delete the document’s “existence.”
“In page 175 of the first-edition ‘Mind Hunter’ book, Douglas describes a woman’s screams and shortly thereafter how the woman’s throat had been cut and her naked body mutilated,” prosecutors said. “Douglas further asserts, on page 175 of said book, that mutilation is a sign of ‘disorganized personality type.””
“Accordingly, this notation contained in the HK Planning Document is again consistent with the aforementioned book in page number and subject matter,” the state alleged.
Pictured: Rex Heuremann’s alleged copy of “The Cases That Haunt Us” as seen in court documents.
Prosecutors further said that Heuermann’s ownership of other Douglas books “in part” supports their claims that he studied serial killer literature, treated it like “homework,” and then applied what he learned in the real world, allegedly committing “serial, sexual murder” he regarded as “play time.”
Read the bail application here.
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