5 chilling details about the Long Island Serial Killer

The case of the Long Island serial killer, also known as the Gilgo Beach murders, remains one of the most complex criminal investigations in New York history. It involves the deaths of at least 11 individuals, many of them s*x workers, whose remains were found along Ocean Parkway between 1996 and 2011.

In 2023, Rex Heuermann, a 61-year-old architect from Massapequa Park, was arrested and later charged with multiple counts of murder.

According to a Newsweek report dated August 26, 2024, prosecutors allege that Heuermann kept victims alive to inflict extended torture. A New York Post report dated June 6, 2024, details a planning document allegedly recovered from Heuermann’s computer, outlining dismemberment procedures and disposal methods.

Meanwhile, Netflix's docuseries Gone Girls: The Long Island Serial Killer examines how years of investigative delays were worsened by law enforcement misconduct. As new details continue to emerge, the Long Island serial killer case is still under investigation, with prosecutors working to link additional victims.

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5 key details about the Long Island Serial Killer explored

1) A detailed “planning document” mapped out the murders

One of the most pivotal pieces of evidence in the Long Island serial killer case is a digital file prosecutors say was recovered from Rex Heuermann’s computer. According to a New York Post report dated June 6, 2024, this “planning document” included multiple sections, such as “Things to Remember,” “Lessons Learned,” and a detailed breakdown of phases labelled “Pre-Prep,” “Prep,” and “Post-Event.”

The file allegedly contained step-by-step outlines on how to abduct, restrain, and dispose of victims. Instructions like “remove head and hands” and “remove ID marks [tattoos]” were consistent with the condition of victims Jessica Taylor and Valerie Mack.

Additionally, the planning file was organized with entries under headings like “PROBLEMS,” “SUPPLIES,” “TRG” (believed to mean “targets”), and “DS” (interpreted as “dump sites”), as described in a report by The Sun, dated December 18, 2024.

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2) Heuermann allegedly studied his crimes and recorded “lessons”

Prosecutors say Heuermann didn’t just document his actions, he evaluated them. As to a Newsweek report dated August 26, 2024, the planning file contained notes on what had worked and what hadn't.

According to a New York Post report on June 6, 2024, among the listed “lessons” were reminders like “hit harder” for future attempts and to use “heavier rope,” citing that a lighter one had failed during a previous incident. Another line read:

“consider a hit to the face or neck next time for take down.”

These statements led Suffolk County District Attorney Ray Tierney to state that the document indicated “intent and methodology” and was more than just fantasy or fiction. The file had reportedly been deleted but was recovered by forensic experts during a search at Heuermann’s home.

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3) Some victims may have endured prolonged torture

Forensic findings suggest that at least two victims, Jessica Taylor and Sandra Costilla, may have been held alive for several days. As per the Newsweek report dated August 26, 2024, prosecutors theorize that Taylor was likely in captivity for up to four days based on phone activity and witness sightings.

Her remains showed signs of dismemberment and postmortem injury. Prosecutors explained that the planning document’s references to “play time” indicated that the Long Island Serial Killer wanted to keep victims alive to prolong control and interaction. Former FBI profiler Gregg McCrary told Newsweek:

“They want to keep them alive as long as they can, reasonably. Killing is what they have to do at the end to not be discovered.”

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4) DNA evidence tied the case back to Heuermann’s household

Multiple reports confirmed that forensic breakthroughs were crucial in linking the accused to the murders. In particular, a report by The Sun, dated December 17, 2024, stated that hair found on Valerie Mack’s remains matched Heuermann’s wife and daughter.

Prosecutors suspect the hairs were transferred via clothing or household objects. Earlier, a pizza crust discarded by Heuermann was collected and tested. The DNA matched a sample found on one of the Gilgo Four victims. This was confirmed in Netflix Tudum dated March 31, 2025.

While none of the family members are suspected to have participated in the crimes, the trace evidence established proximity and timing. This connected Heuermann to the crime scenes, proving him to be the alleged Long Island Serial Killer.

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5) Community unease and law enforcement missteps delayed the case

Gilgo Beach Murders Suspect Rex Heuermann Appears In Suffolk County Court For Hearing (Image via Getty)

Despite residing in a seemingly quiet neighbourhood in Massapequa Park, the alleged Long Island Serial Killer’s presence had long made some residents uneasy.

According to a New York Post report dated March 27, 2025, neighbours avoided his house during Halloween. His unkempt property stood out in an otherwise orderly area. One neighbour described local kids crossing the street to avoid walking past his home.

As per the media outlet, dated March 27, 2025, both officials were later convicted of unrelated crimes. Liz Garbus, director of the Long Island Serial Killer, noted:

“Their No. 1 priority was keeping themselves out of prison.”

The docuseries Gone Girls: The Long Island Serial Killer also revisits the systemic failures that stalled the investigation. Garbus alleged that law enforcement corruption, under former Suffolk County Police Chief James Burke and DA Thomas Spota, obstructed early progress.

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Gone Girls: The Long Island Serial Killer is available to stream on Netflix.