Nuclear DNA testing at issue in Gilgo Beach murder case. Here's what it is.
The Gilgo Beach murder case is moving toward a trial, but two defense requests are slowing things down. Rex Heuermann's attorneys are asking for more time as they challenge something called nuclear DNA testing, which has never been used in a New York court of law.
The judge has set what's called a Frye hearing to determine whether the cutting-edge DNA evidence will be admissible in Heuermann's trial.
While the defense team calls the process "magic," prosecutors say it's commonly used throughout forensic science.
Nuclear DNA hearing in Gilgo Beach murder case begins
The Frye hearing started Friday, kicking off a pre-trial process that could last a few months. Both sides are expected to call a total of eight witnesses, including a doctor and other experts.
Genome scientist Dr. Kelly Harris took the stand Friday. After listing her credentials from Harvard to Cambridge, she gave hours of complex testimony validating that genetic sequencing has dramatically advanced with high-precision nuclear DNA, now considered widely-accepted science.
Nuclear DNA was used to match Heuermann to hairs on belts, tape and burlap found with the seven victims he is charged with murdering.
Harris told the court it is, "embarrassing that a method like this wasn't the state of the art years ago, but better late than never."
While nuclear DNA is used in medicine, it has never been included in a New York criminal trial.
"They want to, in essence, have a jury rely on this, which is not trustworthy, it's not reliable, it's not scientific, and it shouldn't be utilized in a court," said defense attorney Michael Brown.
The Frye hearing will continue to fit the judge's schedule. In the meantime, he could rule on how many trials Heumermann will eventually face. The defense is seeking separate trials for the seven murders, but prosecutors are arguing for a single one, citing overlapping evidence, including a detailed planning document.
What is nuclear DNA testing?
Nuclear DNA testing is common in forensic science, according to Michael Marciano, director of research for Syracuse University's Forensic and National Security Sciences Institute. He said it's used for everything from at-home DNA kits to disease detection and identifying human remains.
"We typically focus on nuclear DNA in forensic science, this is nothing new. It's been done for decades and decades," Marciano explained.
Marciano said the question in the Heuermann case is what is known as whole genome sequencing, which he explained can be a more sensitive type of testing.
"Rather than look at 24 to 27 areas of the DNA, which is what we typically do in forensic cases, we look at thousands, tens of thousands, hundreds of thousands of different variations in the DNA," he said. "If you think about your DNA, a lot of people see it as a sequence of letters. We're looking for differences in those letters.
"We share most of our DNA with each other. We're looking for those differences, and those differences can provide information as to the identity of an individual," he continued.
Shortly after Heuermann's arrest in July 2023, the district attorney's office said DNA from a discarded pizza box linked him to hair from one of the victims.
When Heuermann was charged with a seventh murder last December, court documents said hairs found near the victim's wrists were linked to his estranged wife Asa Ellerup and his daughter, to the exclusion of 99.65% of the North American population. His wife and daughter, who would have been a young child at the time, have not been accused of any wrongdoing in the case.
"This is the future"
If the whole genome sequencing is admissible in this case, Marciano says it could be a game-changer in DNA testing.
"If we look back to the O.J. Simpson case, actually, we saw the introduction of a new technology called PCR-based testing, which is now the gold standard for forensic DNA testing," he said. "Whole genome sequencing is available in private companies right now for use in criminal investigations. It's not widespread, but this could be one of those critical moments in moving forward in forensic DNA analysis that brings this to the mainstream."
He said changes like this take time to work through the court system, but added, "this is the future, without a doubt."
"Innovations in forensic DNA analysis take time, because it goes through the court system, and that benefits the defense as well as the prosecution in the need to vet and ensure that these technologies are reliable," he said. "That is what these hearings that we're expecting in the next two weeks to cover - is this generally accepted? Is this high quality science?"
Heuermann's divorce nearly finalized
Meanwhile, Heuermann's uncontested divorce from his estranged wife, Asa Ellerup, is nearly finalized, but she has reserved judgement on his guilt.
"She has a difficult time throughout this whole process believing the husband that she's married to for 29 years now was capable of committing these horrific acts. It is even more concerning that her hair and her daughter's hair were found on some of these victims. So this process is very important to getting closure for her," said Robert Macedonio, an attorney for Heuermann's wife and daughter.
