Gilgo Beach killings: Attorneys for accused serial killer Rex Heuermann seek to exclude expert nuclear DNA testimony related to hairs found at crime scenes

Attorneys for alleged Gilgo Beach serial killer Rex A. Heuermann have asked the judge in his case to exclude expert testimony related to nuclear DNA results obtained from rootless hairs found at six crime scenes, arguing the technique used by a California laboratory working with Suffolk investigators has not been generally accepted as reliable in the scientific community.

The motion filed Tuesday is the first step in establishing a hearing this winter to determine if the DNA profile obtained by Astrea Forensics linking the Massapequa Park architect to the alleged killings will be admissible at trial.

"There appears to be no precedent from any New York court, or elsewhere in the United States, that the proprietary scientific procedures, methodology or software program employed by [the lab] has ever met the Frye or Daubert standard of admissibility," defense attorney Danielle Coysh argued in the filing.

Suffolk County District Attorney Ray Tierney has conceded the case is the first in New York to test the methods used by the lab, making the hearing necessary.

Suffolk Supreme Court Justice Timothy Mazzei said last month that he intends to schedule the hearing when Heuermann returns to court Jan. 15 and would likely set a date in late February or early March.

Tierney said his office is ready to present the nuclear DNA evidence in court and said prosecutors wouldn't have introduced it if they didn't believe in "the efficacy and the admissibility" of that evidence.

"We're prepared to defend it," Tierney said Tuesday.

The defense motion states prosecutors will seek to introduce the DNA evidence through the testimony of Richard Edward Green, who  co-founded the Santa Cruz-based Astrea Forensics biotech company in 2019. The defense anticipates Green will testify to recovering the single nucleotide polymorphism DNA information through whole genome sequencing of rootless hair samples provided by the task force investigating the case.

Tierney called the DNA work done by Astrea a "key component" in the case, but the defense argues the methods employed by the lab are "fundamentally different" to the techniques used by all other crime labs over the past three decades.

"In addition, the statistical weight Dr. Green attaches to his results are generated in a way that is unlike any that has been used in forensic DNA profiling casework before," argued Coysh, who is representing Heuermann along with lead counsel Michael J. Brown, both of Central Islip.

Officials at Astrea, who have not responded to previous requests for comment, could not be immediately reached Tuesday.

The defense team alleges its investigation into the lab revealed Green has testified about his proprietary technology in just one case in Idaho, a state that has not adopted the same standard of admissibility as New York.

Coysh said the only peer review the defense could identify regarding Astrea’s methods "challenges the validity of Dr. Green’s findings."

Astrea markets itself as a company founded by experts in genomics and ancient DNA methods who use proprietary methods for improving DNA recovery data from the most degraded of samples to help law enforcement agencies solve cold cases.

Brown has criticized Astrea as a for-profit enterprise.

"The way they sell themselves is we are going to solve these unsolved crimes," Brown said of Astrea following the Dec. 17 arraignment charging Heuermann in a seventh killing. "The money they are making in turning this out is enormous. It certainly enriches them."

Tuesday’s filing points to grand jury testimony from Suffolk County Crime Lab forensic scientist Clyde Wells, who the defense argues repeatedly told the grand jury the "rootless hairs were unsuitable for nuclear DNA testing."

But prosecutors have said Astrea’s techniques later helped investigators connect Heuermann and family members with the hairs located at the crime scenes of Maureen Brainard Barnes, Megan Waterman, Amber Costello, Sandra Costilla, Jessica Taylor and Valerie Mack, six of the seven alleged victims in the indictment.

The lab found hair discovered on items recovered from the Costilla, Waterman and Taylor crime scenes are statistically likely to have come from Heuermann himself.

The lab linked other hairs found when the bodies were recovered between 1993 and 2011 to Heuermann’s wives and daughter, which prosecutors allege were transferred from another surface during the killings. Prosecutors have said the evidence linking Heuermann to a seventh alleged victim, Melissa Barthelemy, does not include DNA.

Tierney has repeatedly stated investigators believe Heuermann, who has pleaded not guilty at four separate arraignments since his initial arrest in July 2023, acted alone in the alleged killings of the women, each of whom engaged in sex work and whose bodies were discovered along Ocean Parkway near Gilgo Beach, in Manorville and in North Sea.

By Grant Parpan

grant.parpan@newsday.com@GrantParpan

Grant Parpan covers Suffolk County courts and federal courts for Newsday. A Long Island native, he joined Newsday in 2022.