What Gilgo Beach killer’s wife REALLY knew: Prosecutor reveals truth

She was married to Gilgo Beach serial killer Rex Heuermann for more than two decades, during which time he murdered seven of his eight victims.

She lived under the same roof as him, together raising their children in the Massapequa Park, Long Island, home where he lured, tortured and strangled the young women.

Asa Ellerup has insisted she knew nothing of his crimes.

But, in the three years since he was unmasked as the serial killer, many have questioned how a wife could share a life so closely entwined with a man capable of such horrors and not have suspected anything out of the ordinary.

Now, Suffolk County District Attorney Ray Tierney has revealed for the very first time what investigators learned about her relationship with the serial killer who preyed on young vulnerable women and terrorized Long Island for decades.

In a wide-ranging sit-down interview with the Daily Mail, Tierney exclusively shared new details about Heuermann’s meticulous plans to kill, his victims’ chilling final moments, the investigation to catch the killer, and – in the latest twist in the case – the inner workings of the bombshell plea agreement.

Despite the cloud of suspicion hanging over Ellerup, Tierney insisted that the years-long investigation uncovered zero evidence that she knew anything about her husband’s killing spree.

‘Nothing at all. I think she knew that there were other issues with the defendant, but there’s no evidence whatsoever to think that she knew he was murdering people. Absolutely not,’ he said.

However, while Ellerup was in the dark about his double life as a serial killer, Tierney cryptically said that she was likely aware that her husband had ‘other issues’ or ‘other interests.’

Rex Heuermann and Asa Ellerup at their 1995 wedding – two years after he allegedly killed his first victim

Asa Ellerup faces questions outside court asking what she knew about her former husband’s crimes

When pressed if she was aware he was cheating on her with sex workers, the prosecutor simply said: ‘I think that he she was aware that he had other interests.’

Through the years-long Gilgo Beach killer investigation, Tierney said it became clear that the relationship dynamic between Heuermann and Ellerup was ‘not typical,’ with the serial killer controlling all aspects of their home life and finances.

‘Normally with offenders, especially when there is obsessive behavior, they don’t tend to associate themselves with people who are very suspicious,’ Tierney said.

He pointed out that, in typical relationships, spouses tend to know about each others’ finances and whereabouts – but this didn’t seem to be the case in their marriage.

‘I don’t think that was the dynamic in this particular relationship,’ Tierney said.

‘Rex liked to control. He controlled the finances. He really controlled everything. I don’t think that their dynamic was typical.’

Heuermann was also ‘a prolific purveyor or consumer of escorts,’ Tierney said, ‘the vast majority of which obviously he didn’t murder.’

Ellerup was 18 and working in a 7-Eleven when she first met Heuermann. They both married other people.

In the Peacock docuseries The Gilgo Beach Killer: House of Secrets, Ellerup said that her first marriage ‘did not go well at all’ after their son Christopher was born.

She described Heuermann as her ‘hero’ who helped her through her divorce and took her and Christopher into his home.

Rex Heuermann in court on April 8, 2026, where he pleaded guilty to the murders of seven women – and admitted to an eighth

The victims clockwise from top left: Sandra Costilla, Karen Vergata, Melissa Barthelemy, Valerie Mack, Megan Waterman, Amber Costello, Maureen Brainard-Barnes and Jessica Taylor

But she was not the only person in Heuermann’s life fooled by him masquerading as a family man and businessman.

Through his own interactions with Heuermann, Tierney said he found the 62-year-old architect to be ‘meticulous’, ‘manipulative,’ ‘smart’ and with ‘above average intelligence.’

‘He is very good at portraying himself to be who he thinks you want him to be,’ he said.

‘That’s why I think not only his family, but also the people who knew him, worked with him and were friendly with him never thought that he would be capable of what he’s been convicted of.

‘I think he liked living in that sort of space where he was not what he seemed to be.’

Tierney said that investigators received ‘incredible cooperation’ from Heuermann’s family members and all others connected to the case, including when it came to the crucial DNA evidence.

A total of nine hairs belonging to Heuermann, Ellerup, their daughter Victoria Heuermann and another woman who once lived with the killer were found on six of the seven victims whose murders he was charged with.

Heuermann’s family – Ellerup, Victoria and Ellerup’s son Christopher Sheridan – was out of town on vacation at the time of each of the murders.

Suffolk County DA Ray Tierney sat down with the Daily Mail for a wide-ranging interview about the case

Suffolk County DA Ray Tierney holds a press conference with the victims’ families and law enforcement after Heuermann’s guilty pleas 

At the time of the first known murder of Sandra Costilla in 1993, Heuermann was living alone, Tierney said.

‘With all the victims, we wanted to show that the defendant would have unfettered access to the victims through the home, meaning that nobody else was around,’ he said.

On April 8, Heuermann finally confessed to the murders of eight women over a 17-year reign of terror between 1993 and 2010.

His victims – Sandra Costilla, 28, Melissa Barthelemy, 24, Megan Waterman, 22, Amber Costello, 27, Maureen Brainard-Barnes, 25, Jessica Taylor, 20, Valerie Mack, 24, and Karen Vergata, 34 – were all young women who had been working as sex workers when they suddenly vanished. 

Their remains – some of them mutilated and dismembered, others bound with belts and wrapped in burlap – were found dumped in remote areas of Long Island.

Fears of a serial killer first emerged back in 2010 when the remains of the first of 11 bodies were discovered along the remote stretch of Ocean Parkway, close to Gilgo Beach.

The harrowing discovery came during a search for 24-year-old Shannan Gilbert, who had made a chilling 911 call and then disappeared following a visit to a client’s house in nearby Oak Park that May.

That December, Barthelemy’s remains were the first to be found. Within days, Brainard-Barnes, Waterman and Costello were found close by.

By the spring of 2011, 10 victims had been found in the area. The final victim found was Gilbert, who, to this day, investigators maintain died by accident and is not linked to the serial killer case.

Asa Ellerup and Rex Heuermann were married for more than two decades and lived in the home where he lured and killed his victims

Rex Heuermann’s Massapequa Park home where police conducted multiple searches

Another 13 years would pass before a suspect fell on investigators’ radar, after Tierney entered office and launched the Gilgo Beach Task Force comprising multiple law enforcement agencies.

Heuermann was ultimately tied to the serial killings through a witness tip about his pickup truck as well as damning cellphone evidence and was arrested in July 2023.

Ellerup filed for divorce in 2023 days after his arrest, though she continued to stand by him. 

Over the past two-and-a-half years, Heuermann fought the allegations while new murder charges mounted.

In a sudden reversal, he changed his plea to guilty on all seven murders for which he was charged – and also admitted to the murder of an eighth victim, Karen Vergata.

For the first time, he revealed how all of the women died by strangulation. 

Under the plea agreement, Heuermann has waived all rights to appeal and will not face any additional charges over the eight murders. He has also agreed to cooperate with the FBI’s Behavioral Analysis Unit.

He faces multiple life sentences at his sentencing on June 17.