ALLEGED Gilgo Beach serial killer Rex Heuermann used burner phones to trawl Tinder and call dozens of escort services in the months leading up to his arrest, according to court documents.

Suffolk County prosecutors allege the digital evidence reflected a consistent pattern spanning over 15 years that showed Heuermann was a “sexual sadist.”

Accused Gilgo Beach Killer Rex Heuermann Attends Court Hearing
Alleged Gilgo serial killer Rex Heuermann (right) appears for a hearing on January 13Credit: Getty
 

Aerial view of Rex Heuermann's home in Massapequa Park, New York, showing a yellow excavator next to the house and a large area of disturbed earth.
Authorities work at the home of Heuermann in Massapequa Park, on Long Island, NYCredit: AP

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A map of six of the seven victims Heuermann is alleged to have killed and where their remains were locatedCredit: Supreme Court of Suffolk County
 

A crime laboratory officer in a hazmat suit carries a blue box of items away from a house.
A crime laboratory officer removes a box of items as law enforcement searches the home of Rex HeuermannCredit: AP

One phone recovered by investigators showed that between January 2021 and March 2022, Heuermann allegedly contacted 56 sex workers or massage parlors over 300 times.

Prosecutors also alleged that between December 2021 and February 2023, Heuermann used another phone to contact 61 escort service numbers, reaching out on over 220 occasions.

The hulking architect, 62, from Massapequa Park in Nassau County, Long Island, is charged with the murders of seven women, all of whom were found scattered across Long Island between 1993 and 2010.
The women have been identified as Sandra Costilla, Valerie Mack, Jessica Taylor, and Maureen Brainard-Barnes, Melissa Barthelemy, Megan Waterman, and Amber Lynn Costello – the latter four collectively known as the Gilgo Four.

He has pleaded not guilty to all counts.

‘Consistent pattern’

“When analyzing this search warrant affidavit and the ones that follow, the significance of the defendant’s recent use of burner phones to patronize sex workers cannot be dismissed,” prosecutors wrote in their motion filed on Tuesday.

“This evidence was not offered to ‘vilify’ the defendant for his sexual conduct, as he so claims, but rather to establish the defendant’s identity and modus operandi, as the defendant similarly used burner phones to arrange encounters with the victim sex workers between 2007 and 2010.”

Prosecutors added, “Far from impermissible character evidence, such evidence is directly relevant as it reflects a consistent pattern spanning over 15 years, which the issuing Judge could logically and rationally have inferred was part of defendant’s current and former modus operandi to not only commit these murders, but also to avoid apprehension and prosecution.”

Heuermann was arrested in July 2023 outside his office in Midtown, Manhattan, after investigators matched his DNA from a discarded pizza crust to hair found on a victim.

It is unknown what the married father-of-two was doing in the years leading up to his arrest nearly three years ago.

However, Heuermann was allegedly active on the dating platform Tinder in 2022, seeking “dates” and “hookups” within his vicinity, according to court records filed by prosecutors.

Collage of photos of Melissa Barthelemy, Amber Costello, Megan Waterman, and Maureen Brainard-Barnes, victims of the Gilgo Beach murders.
A combination of images shows the Gilgo Four victims: Melissa Barthelemy (top left), Amber Costello (top right), Megan Waterman (bottom left), and Maureen Brainard-BarnesCredit: AP
 

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Sandra Costilla’s remains were found in a wooded area in Southampton in November 1993Credit: Family Handout
 

Mugshot of Valerie Mack, a woman with long wavy brown hair and light eyes.
Valerie Mack went missing in the spring of 2000, and her remains were found in September of that yearCredit: AP
Digital evidence showed that in March 2022, Heuermann allegedly created a Tinder account under the aliases “Andrew Roberts and Thomas Hawk,” investigators alleged.

Prosecutors alleged his Tinder profile was under the pseudonym “Andy.”

Investigators accused Heuermann of using the false name and email addresses to mask his identity.

Officials said evidence showed Heuermann kept the burner devices near a phone registered under his actual name.

Disturbing ‘online searches’

The disturbing details were revealed in a 122-page motion filed by the Suffolk County district attorney’s office.

The filing obtained by The U.S. Sun was in response to a defense motion to suppress certain evidence from trial, which is slated to begin in September.

In the recent filing, prosecutors said that before his arrest, Heuermann also searched for images of his alleged victims’ family members.

Heuermann allegedly conducted over 100 online searches related to the Gilgo Beach killings and other murders.

Prosecutors said the search inquiries included “Why hasn’t the long island serial killer been caught,” “Map of all known serial killers,” and “Cops launch Gilgo Beach Homicide Investigation Task Force.”

A false email address linked to one of Heuermann’s burner phones allegedly showed that he also attempted to access pornography related to “bindings, torture, rape, snuff videos, crying, bruised and impaled women and/or girls.”

At the time of his 2023 arrest, prosecutors alleged that Heuermann conducted online searches and read news articles about the grisly murders.

Between May and June 2022, Heuermann alleged made specific searches about Brainard-Barnes, Barthelemy, Waterman, and Costello, and the investigation into their killings, court records showed.

Despite facing seven counts of murder, investigators believe Heuermann could potentially be tied to the death of several other victims who have been found on Long Island throughout the years.

Suffolk County District Attorney Ray Tierney previously said his office refused to consider offering Heuermann a plea deal.

Tierney said his team is ready to move forward to trial.