Gilgo Beach killings: New DNA technology's admissibility to be tested in case against Rex Heuermann

When Rex A. Heuermann was charged a year ago in the deaths of three of the Gilgo Beach victims — a total that since has expanded to six victims — Suffolk County District Attorney Ray Tierney credited advances in DNA technology with helping buttress the evidence against him.

As the case against Heuermann, 60, moves closer to trial, new DNA methods will come under scrutiny by the court, which will have to decide whether the methodologies, including groundbreaking methods of analyzing human hair and other DNA material, can be presented in court.

Heuermann has pleaded not guilty to multiple counts of first-degree and second-degree murder charges.

The DNA techniques are being used for the first time in New York, setting the stage for a high-stakes battle of prosecution and defense experts.

Tierney and defense attorney Michael J. Brown are expected to call experts for a pretrial proceeding known as a Frye hearing, named after a 1923 federal court ruling in Frye v. United States that spelled out procedures for testing “novel” scientific evidence to be used in a criminal case.

While Tierney noted in an interview that some of the new methods have been approved for use by other courts, New York courts have yet to rule on their admissibility.

Heuermann’s defense team will try to keep any significant DNA out of the case, said Bruce Budowle, a nationally known DNA scientist who was involved in the establishment of the FBI’s national DNA database.

“One thing they are going to do is find experts to attack [DNA evidence],” Budowle said.

The aim of a Frye hearing would be to determine if DNA techniques used by prosecutors to indict Heuermann are accepted by the scientific community. Under the law, there doesn’t have to be unanimity among scientists about the viability of the methodology, just general acceptance.

“The prosecutor is going to have to convince the judge that it is accepted in the scientific community,” said Robert C. Gottlieb, a Manhattan defense attorney who has handled several Fyre hearings. “The judge becomes the arbiter not only of the law [but also] the facts.”

Suffolk prosecutors have said that Heuermann's cheek swab DNA matches his genetic material found on a pizza box they said he discarded in a trash can near his Manhattan office before he was arrested. Tierney has said numerous times that the DNA evidence is crucial to the prosecution. While police have other evidence, such as cellphone records and Heuermann’s own so-called “manifesto” found during a search of his computers, a court ruling keeping out the DNA evidence would make a guilty verdict more difficult.

“In any case where a witness to the crime is no longer there, you have to prove the case through other means,” Tierney said. “You try to layer evidence that corroborates each other. Obviously DNA is a key component in corroborative evidence; you can’t rely on it only.”

What has proved crucial in the case against Heuermann was the recently developed capability of forensic laboratories to examine about a half-dozen human hairs found on victims — Maureen Brainard-Barnes, Amber Lynn Costello and Megan Waterman — and link them to Heuermann and his female family members.

Tierney and court papers said additional genetic analysis of hairs found on the bodies of Jessica Taylor and Sandra Costilla were linked to Heuermann.

In 2010 and 2011, when the first remains of the Gilgo Beach victims were found, the Suffolk County Office of the Medical Examiner didn’t have the capacity to examine human hairs to develop DNA profiles. The hair shafts appeared to lack roots, which could have been helpful in finding usable DNA.

Through the work of two outside private laboratories, identified by Tierney in court papers as “Laboratory #1” and “Laboratory #2,” scientists were able to develop genetic profiles of the mitochondria found in the rootless hairs. Mitochondria are small bodies located in human cells, which have their own DNA. The mitochondria are resilient and have a better chance of not being degraded, compared with the nuclear DNA of a cell.

A mitochondrial DNA strand is relatively short and, unlike nuclear DNA, cannot alone provide enough data to make an exact match to a suspect, as often depicted in police procedural shows such as “CSI.” Instead, DNA analysts can only calculate certain probabilities that the mitochondrial sample is linked to a person.

In the first indictment against Heuermann in July 2023, Tierney revealed that DNA of rootless hairs found on the bodies of Brainard-Barnes, Costello and Waterman were analyzed by Laboratory 1 and found to be female hairs, all from the same mitochondrial grouping. Later, testing by Laboratory 2, which specializes in mitochondrial analysis, determined that DNA found on beer bottles from the trash outside the Heuermann house in Massapequa Park was from the same mitochondrial grouping as the hairs on the three Gilgo remains, court papers show.

Additional testing of consent DNA samples of Heuermann’s wife, Asa Ellerup, and the couple’s daughter, Victoria, showed they were the sources of mitochondrial DNA of hairs found on the bodies and the bottles. Tierney repeatedly has said neither Ellerup nor her daughter is suspected of any wrongdoing.

The more crucial mitochondrial DNA hit came from a solitary male hair found on burlap used to bind Waterman’s body. Testing by Laboratory 1 determined the mitochondria of the hair came from a particular genetic group. More testing of the solitary hair by Laboratory 2, which compared it with DNA from a pizza box Heuermann handled, found the mitochondrial profiles were the same.

Such similarities can’t be used to make identification of a suspect, only circumstantial evidence of identification — albeit strong evidence. Tierney said in court papers that the analysis of the single male hair excluded 99.96% of the North American population as the source of the male hair but that Heuermann couldn’t be excluded as the source. 

While the mitochondrial DNA finding was deemed significant by prosecutors, it left open the possibility that another man could have been the source of the hair. Defense attorney Brown made that point when he said thousands of men could be included in the mitochondrial profile. Brown didn’t return a call for comment for this story.

In January, prosecutors revealed that newly developed forensic methods allowed Laboratory 1 to extract some nuclear DNA from the hairs, most importantly the solitary male hair found on Waterman. The analysis determined that so-called SNPs, which are relatively short strands of genetic information, found in the nuclear DNA were similar to those found in a cheek swab given by Heuermann under a court order.

In court papers, Tierney put the likelihood that Heuermann was the source of the Waterman male hair as being millions of times more likely than not. Thus, the SNP comparison was stronger circumstantial evidence tying him to Waterman when she died, Tierney argued in his court papers.

Arguments by the defense and prosecution about whether new methods of analyzing nuclear DNA from hair samples are accepted by a significant part of the forensic community likely will be a major battle in the pretrial hearings.

Another issue that might surface in the case centers on whether the two private laboratories used by Tierney and the Gilgo Beach task force have the necessary permits to do DNA testing in New York State.

Under state Department of Health regulations, private laboratories doing DNA analysis for police and prosecutors needed to be vetted and issued permits by the Health Department. Currently, there are four such labs given such approval, said Danielle R. De Souza, a Health Department spokeswoman.

The state agency said one of the labs with a permit is Mitotyping Technologies LLC, of Pennsylvania, which specializes in mitochondrial analysis. Officials at Mitotyping Technologies didn't return a request for comment.

Court filings by Tierney indicated in a footnote that another laboratory used in the investigation was Astrea Forensic, of California, which has pioneered new methods for getting nuclear DNA from rootless hair samples. Officials at Astrea repeatedly have declined to answer email and telephone queries.

Gottlieb also believes earlier delays in the Gilgo investigation — before 2022, when James Burke was in charge of the Suffolk County Police Department — could raise the issue of mishandled DNA evidence, something Heuermann’s defense may explore.

“Jurors are definitely swayed by scientific evidence, more so than any writing [Tierney] is characterizing as a manifesto,” Gottlieb noted.

By Anthony M. DeStefano

tony.destefano@newsday.comtonynewsday

Anthony M. DeStefano has been a reporter for Newsday since 1986 and covers law enforcement, criminal justice and legal affairs from its New York City offices.