A Long Island judge will soon determine whether to allow some evidence central to the case against accused serial killer Rex Heuermann.

Investigators have linked the 61-year-old architect to the murders of seven women whose bodies were found dumped along a beach on the south shore of the island in part by DNA found on hair fibers at some of the crime scenes.

They used a new system to test the DNA, known as whole genome sequencing – in which scientists take all of the fragments of DNA and assemble them on a human genome, to link the fibers to Heuermann, according to ABC 7.

But defense attorneys argue that the novel testing system has never been cited in the New York courts system before – and should therefore be considered ineligible to be brought at a trial.

Prosecutors, however, have argued that the technique is already widely used in the medical community and is consistent with what the court system has allowed in the past.

They also note that the findings by Astrea Forensics, a California-based lab, were also independently corroborated by mitochondrial DNA testing – which has long been accepted by the New York courts system.

A hearing on the matter is now scheduled to begin on Friday, with both sides expected to call a total of eight witnesses, including a doctor and other experts, without a jury present, CBS News reports. 

It comes as Suffolk County District Attorney Ray Tierney says the case is ‘heading toward the trial phase,’ noting that the investigation process is ‘pretty much closed,’ according to Newsday.

Attorneys representing accused Long Island serial killer Rex Heuermann, 61, have argued in court documents that DNA evidence should not be used at his trial

His attorneys are also seeking to have the case against him split up into five different trials

Investigators have linked the 61-year-old architect to the murders of seven women whose bodies were found dumped along a wide beach on the south shore of the island in part by DNA found on hair fibers at some of the crime scenes

Police had been investigating the deaths of at least 10 people — mostly female sex workers — whose remains were discovered along an isolated highway not far from Gilgo Beach on Long Island’s south shore since 2010.

They had long believed the victim – eight women, a man and a toddler who had disappeared over a span of at least 14 years – were all killed by the same person.

Among the victims were Jessica Taylor, who vanished in 2003 while working as an escort in New York City. Some of her remains were discovered in Manorville later that year. 

She had been decapitated and both of her arms were severed. Moreover, a tattoo on her torso had been ‘severely obliterated by a sharp object,’ per officials.

Other remains were found in a 2011 search of the beach scrub by the side of Ocean Parkway, the road where the other Gilgo Beach victims were found. 

Prosecutors now say Heuermann was intimately familiar with the area, as he worked at Jones Beach State Park down the highway for three years.

‘Part of defendant’s work at the beach entailed the defendant getting on All-Terrain Vehicle and going from field to field to ensure beachgoers were off the property once the beach was closed, a role that made the defendant extremely familiar with Ocean Parkway at night,’ prosecutors argue in court documents obtained by Newsday.

Originally, Heuermann was just charged with the murders of Melissa Barthelemy, Megan Waterman and Amber Costello. 

As prosecutors continued to investigate, however, they also charged him in the deaths of Maureen Brainard-Barnes, Sandra Costilla and Jessica Taylor.

Then, in December, Heuermann was also indicted for the 2000 killing of Valerie Mack, a 24 year-old Philadelphia woman who vanished 24 years ago. Partial remains were found in Manorville, Long Island, in November that year.

He has pleaded not guilty to the murders, and his lawyers now want to have the case against him heard at five different trials.

They have argued that their client risks being improperly convicted due to the ‘cumulative effect’ of the evidence put forth by prosecutors, and said there is a ‘substantial disparity’ in the evidence of some of the deaths – which they say involves different time frames, killing methods and locations for disposing the bodies.

‘The danger of having count after count, victim after victim in the same trial  is that “If there’s smoke there’s fire” mentality,’ lawyer Michael Brown argued.

‘They shouldn’t be tried together. One issue has nothing to do with the other.’ 

Heuermann was arrested in the summer of 2023, and was originally just charged with the deaths of three women. But as prosecutors continued to investigate, they linked him to four others 

Yet Suffolk County prosecutors have maintained that Heuermann likely committed all of the homicides – claiming there is overlapping evidence and calling it a serial killer case.

‘This is an individual who had the specific intent to kill, identify, locate, lure, obtain control over and murder multiple victims,’ DA Tierney said.

He pointed to what investigators have called a ‘blueprint’ of the alleged serial killer’s crimes, that he kept on his computer. 

In the document, Heuermann allegedly laid out a set of tasks to complete before, during and after killings, including checking the weather and setting up a staging area. It also has a place to note practical lessons for ‘next time.’

One section, titled ‘BODY PREP,’ included guidance to ‘REMOVE HEAD AND HANDS,’ as well as tattoos and ‘marks of torture.’ Heuermann allegedly also left a reminder for himself to wash the ‘inside and all cavities’ of his victims.

Another section, ‘THINGS TO REMEMBER,’ appears to highlight lessons from previous killings that should be heeded, according to prosecutors.

The entries describe the importance of sleeping properly ‘BEFORE HUNT,’ using thick rope, and limiting noise to increase ‘PLAY TIME.’ 

In a section titled ‘POST EVENT,’ there were reminders such as ‘change tires,’ ‘burn gloves,’ ‘dispose of pics,’ and ‘have story set.’