Did he know that his time was up?
His alleged internet searches would certainly seem to suggest so.
He searched for details about the victims and their families.
He googled the use of new phone technology in the case and looked for podcasts and documentaries about the murders.
And he even took a keen interest in the newly-launched task force – headed up by newly-appointed Suffolk County Police Commissioner Rodney Harrison – that was actively hunting for him.
For up to 16 years, police say he had gotten away with brutally murdering young women and dumping their bodies along the shores of Gilgo Beach in Long Island.
As body after body lay undiscovered, he added more victims to his graveyard, prosecutors allege.
Then, in late 2010, a search for another missing woman led authorities to the grim discovery.
But the suspect’s time still wasn’t up.
For more than a decade, the accused killer continued to go about his day to day life – going to work at his architecture firm in Manhattan and coming home to his wife and two children.
He seemed just as baffled by his lack of arrest as the local residents and victims’ families who questioned why police had not been able to catch the killer.
He even searched Google for the answers to questions including “why could law enforcement not trace the calls made by the long island serial killer” and “why hasn’t the long island serial killer been caught”, court documents state.
Was he looking over his shoulder? Did he have an inkling that he was under surveillance?
Or after all this time had passed, did he think that he might never get caught?
Then, on 13 July 2023, as he left his office in Midtown after a day’s work and walked along a busy Manhattan road, a group of suit-clad men approached and surrounded him.
The gig was finally up.
Rex Heuermann – a 59-year-old married father-of-two, professional architecture, Manhattan business owner and Long Island native – was arrested and charged with the murders of Megan Waterman, Melissa Barthelemy and Amber Costello.
He was also named as the prime suspect in the murder of a fourth woman Maureen Brainard-Barnes, who was last seen alive in New York City in early June 2007.
It’s taken 13 years but Suffolk County Police finally say they’ve caught the serial killer who lured in sex workers, brutally murdered them and then dumped their bound and wrapped bodies along the shores of Gilgo Beach.
What led them to the suspected killer has since been laid out in court documents.
It consisted of a tip about his pickup truck, a stash of burner phones, “sadistic” online searches, phone calls taunting victims’ families, his wife’s hair – and a pizza crust.
How did they find the Gilgo Beach killer suspect?
A sighting of pickup truck believed to belong to Rex Heuermann
The first piece of the puzzle came when a witness in the Costello case revealed details about a vehicle that a client was driving when she was last seen alive.
Costello, who worked as a sex worker, was seen alive on the evening of 2 September 2010 when she left her home in West Babylon.
One night earlier, witnesses said that a prostitution client had come to her home but the client was subjected to a ruse where a man posing as Costello’s outraged boyfriend showed up and made him leave – in a move to swindle the client out of cash. A witness said that the client was driving a first-generation Chevrolet Avalanche.
The next day the same client contacted Costello to meet her but said that he wouldn’t come to her home because of “her boyfriend”, the court documents state.
Costello left her home and was never seen alive again.
The details of the vehicle came to light last year after a new taskforce was assembled in January 2022 to solve the serial killings once and for all. The taskforce reviewed the evidence gathered in the case and investigators interviewed Costello’s pimp in the spring of 2022.
He told officials about the suspect in the green Chevrolet Avalanche, telling them he didn’t know the man’s name but that “you might want to look at him”.
In March 2022, a registration search showed that local man Mr Heuermann owned a first-generation model of the truck at the time of Costello’s disappearance. He also matched the witness’ description of the man believed to be the killer: a large, white “ogre”-like male in his mid-40s, around 6’4’ to 6’6” tall, with “dark bushy hair,” and “big oval style 1970’s type eyeglasses”.
“As described below, this was significant, because a witness to the disappearance of Amber Costello identified a first-generation Chevrolet Avalanche as the vehicle believed to have been driven by her killer,” the court documents state.
Suffolk County Police Commissioner Rodney Harrison told New York Daily News this was the “turning point” in the investigation – and the moment that authorities zeroed in on Mr Heuermann.
“The turning point was the car,” he said. “Once we got that car, who it connected to, that’s when the investigation got legs.”
The discovery of the car led investigators to hone in on Mr Heuermann including executing 300 subpoenas, search warrants and other legal processes to obtain evidence to determine his potential involvement in the killings.
Rex Heuermann’s alleged stash of burner phones
Mr Heuermann’s alleged use of burner phones then led police to make an arrest.
At the time when the three women went missing, they had been in contact with a person who was using a burner phone to arrange to meet them.
People often use burner phones for illicit or illegal activities as they are more difficult to trace.
But, according to the court documents, Mr Heuermann still managed to make a series of critical errors while using them.
The burner phones used to contact the victims always pinged off the same cell towers as Mr Heuermann’s legitimate cellphone, the documents show – indicating that while using the burner phones, he was also in possession of his cellphone at the same time.
The burner phones also pinged off cell towers in two key locations – close to Mr Heuermann’s office in Midtown Manhattan and close to Mr Heuermann’s family home in Massapequa Park.
Records show that Mr Heuermann’s personal cellphone and the burner phones were in the same locations at the same time – and in the locations that corresponded with the disappearances and murders of each of the three women around Massapequa, Long Island and Midtown Manhattan.
“Investigators could find no instance where Heuermann was in a separate location from these other cellphones when such a communication event occurred,” the court documents state.
In the days leading up to Barthelemy’s disappearance, she had been contacted by the same burner phone multiple times.
The last contact from the phone came on 10 July 2009 when she was last seen alive in New York City.
Cell site records show the burner phone traveled from Massapequa Park to Midtown Manhattan that day.
Then, chillingly, Barthelemy’s own cellphone traveled from Midtown Manhattan to Massapequa Park.
Gilgo Beach victims’ cellphones and taunting calls to grieving families
The killer took at least two of his victims’ cellphones after their murders as a trophy – and, in a sick move, called one of the victim’s families from her phone to taunt them about what he had done.
Prosecutors say the evidence shows this person was Mr Heuermann.
Following Brainard-Barnes and Barthelemy’s murders, the killer took and used their cellphones.
Barthelemy’s last cell site location was in the early hours of 11 July 2009 in Massapequa.
Throughout the next two months, the killer then used her cellphone to make taunting phone calls to Barthelemy’s family members.
In at least one of those calls, answered by a devastated family member, the male caller gloated about killing and sexually assaulting Barthelemy.
Prosecutors allege that Mr Heuermann made those cruel calls from or in the vicinity of his Midtown office where his own daughter is now an employee. Records show that each of the taunting calls pinged off cell towers in Midtown Manhattan.
Mr Heuermann also allegedly used Brainard-Barnes’ cellphone to check her voicemail, the court documents show.
Rex Heuermann’s alleged online searches for explicit images – and the LISK investigation
In the years after the murders, Mr Heuermann allegedly continued to slip up in his use of technology – as he allegedly continued to use burner phones to illicit sex from sex workers right up until his arrest.
While it showed a pattern of behaviour, prosecutors also point to other disturbing activity traced to the cellphone numbers.
Court documents show that Mr Heuermann had Tinder profiles and several email accounts under a series of fake names.
He used these accounts – linked to his burner phones – to search for graphic images of young girls and children and “sadistic, torture-related pornography”.
Searches included “girl hog tied torture porn” and “10 year old school girl”.
As well as the disturbing sexual searches, prosecutors say he also looked up images of the murder victims and their relatives, and researched podcasts, documentaries and news stories on the case.
These included “why could law enforcement not trace the calls made by the long island serial killer”, and “why hasn’t the long island serial killer been caught”, “Long Island killer” and “Long Island serial killer phone call”.
He also looked for information about the new task force on the case.
Knowing he was keeping a close eye on the investigation, police kept the developments close to the vest.
Surveillance footage captured Mr Heuermann adding credit to one of the burner phones – and he had it on him when he was arrested.
How was Rex Heuermann’s wife’s hair at the crime scene?
In a bombshell twist, hair belonging to Mr Heuermann’s wife was allegedly found on the bodies of three of the four victims.
Prosecutors say that two female hairs had been found on Waterman, one of them on the tape which the killer wrapped around her head. One female hair was found on tape used to wrap burlap around Costello and one hair was found in a belt buckle used to bind Brainard-Barnes – who Mr Heuermann is yet to be charged over.
To identify the female who the belonged to, investigators trawled through the trash at the Heuermann home in Long Island.
In July 2022, they recovered 11 bottles from the trash and they were swabbed for DNA.
Forensic testing found that the DNA on the bottles matched the female hair found at the crime scene, concluding that the hair belonged to Mr Heuermann’s wife.
The accuracy is such that more than 99 percent of the North American female population can be ruled out, according to the court documents.
Prosecutors found that the suspect’s wife was out of town at the time of the three murders for which he has been charged but that her hair could have transferred to the crime scene through her husband’s clothing or through him using items such as tape taken from the family home.
How a pizza crust was used to match DNA evidence
As well as his wife’s DNA, Mr Heuermann’s DNA was also found on one of the victims.
Prosecutors said that a male hair had been found on the burlap used to wrap Waterman’s body before the killer dumped her along Gilgo Beach.
When the hair was first retrieved in 2010, it was unsuitable for DNA analysis, according to the court documents.
But that hair was kept safely locked away and was submitted for analysis in 2020. A DNA profile came back.
Now, to check if it matched Mr Heuermann, investigators needed his DNA to compare the samples.
This January, a surveillance team watching the suspect saw him chuck a pizza box into the trash close to his office in Manhattan.
They nabbed the box and found a leftover pizza crust inside.
The forensics later came back: it was Mr Heuermann’s hair found on Waterman’s body.