Justice Timothy P. Mazzei concluded Sept. 3 that Astrea Forensics, which conducted the genetic analysis for the prosecution, used a method "generally accepted as reliable within the scientific community." Astrea was hired to analyze old rootless hairs found on the bodies of women who Rex Heuermann is accused of killing.
This marked the first time whole genome sequencing and the program IBDGem, used to analyze the DNA results, cleared these standards, established by the 1923 U.S. Supreme Court decision in Frye v. U.S.
, on which New York relies.Former Sacramento County District Attorney Anne Marie Schubert, who deployed similarly cutting-edge DNA testing methods to identify the so-called Golden State Killer as Joseph James DeAngelo in 2018, said this decision "creates a precedent."
Justice Mazzei's ruling gives attorneys something to build on, even if they practice outside of New York state, Schubert saidplai, exning that although California uses different admissibility standards, judges in all jurisdictions will likely be moved by this ruling.
"It's definitely an exciting time to be in law enforcement and in cold cases, where you can now move cases forward that maybe you couldn't move forward before," Schubert said. She noted that the Combined DNA Index System, or CODIS, a database maintained by the FBI containing suspect DNA and crime scene samples, still contains more than 1.4 million genetic profiles of unidentified potential suspects.
Schubert said it was her hope that law enforcement would be given the financial resources needed to employ the whole genome sequencing and DNA analysis techniques used in the Gilgo Beach case to investigate cold cases where DNA samples may be degraded or limited, preventing the use of traditional DNA testing methods.
Physical evidence against Heuermann consisted of five old rootless hairs found on bodies of his alleged victims. Due to the age of the hairs and their lack of roots, investigators could not use traditional DNA analysis techniques on them, court records show.
However, Dr. Richard "Ed" Green, who founded Astrea, which provided the DNA analysis in the Gilgo Beach case and gave crucial testimony to support the admissibility of his work, said he did not expect to suddenly be inundated with requests following this court decision, because in most cases there are other options.
"It's not a huge operation, we deal with the most difficult samples," he said of Astrea.
Green said the science behind whole genome sequencing was not new when he began using it to identify the mummified remains of a girl discovered in a casket in 2016 beneath a San Francisco home. Green explained that he determined the girl was Edith Cook who died in 1876, using only strands of her hair.
"Getting the DNA out and sequencing — the analysis part of it, that's the new part," he said.
In his order, Justice Mazzei wrote that "neither of defendant's expert witnesses controverted Astrea Forensics' use of whole genome sequencing, to extract DNA from rootless hairs," saying there was little dispute that it was scientifically sound.
Astrea used "shotgun sequencing" to analyze the DNA fragments present in the five hairs to reveal as much of the genome as possible, prosecutors say. The company then used a computer program called IBDGem to compare the genetic material found in the evidence with genetic material taken from the Heuermann family's trash.
Traditional DNA testing works by looking at the number of repeated patterns of nucleotides, the building blocks of DNA, in two genetic samples, to see if they match.
The newer testing method looks at the identity of individual nucleotides at a given location in a genome. These minute differences, called single nucleotide polymorphisms, or SNPs, are the most common type of genetic variation. IBDGem looks at SNP data from two samples and calculates a likelihood ratio for a match between them. Prosecutors say in court filings that the likelihood ratios Astrea calculated overwhelmingly favor a match between genetic material in the hairs and Heuermann and his family.
His family is not charged, nor is an unknown witness who lived with the family and whose hair was also allegedly found on one victim.
Heuermann, who has pled not guilty to killing seven women, worked in New York City as an architect and lived in the Long Island hamlet of Massapequa. He was initially investigated after an eyewitness identified his vehicle make and model as the one driven by a man last seen with victim Amber Costello, according to an application filed by prosecutors opposing bail after his 2023 arrest. The victims were found in some cases decapitated and dismembered in Suffolk County, New York, with many dumped along a stretch of Gilgo Beach.
While the facts in this case are "horrific," attorney Jennifer Lynch of the Electronic Frontier Foundation, a nonprofit dedicated to ensuring technology supports freedom and justice, said she had concerns regarding the precedent New York has set regarding this DNA analysis method.
"Will it be used not just on a hair sample, but will it be used on a piece of fabric that might be degraded or contain multiple contributors?" Lynch said.
She also was troubled by the fact that the IBDGem software passed into admissibility while not being truly independently validated.
"The defense takes issue that all of the validation studies were performed by the man who invented this technology," Lynch said, arguing that "the court brushes it off."
In his decision, Justice Mazzei quoted state court precedent, writing "it has been held that the fact that a developer of a computer software program was involved 'in many of the validation studies does not preclude a determination of general acceptance as a matter of law.'"
Lynch thought this was worrying.
"If it wasn't independently validated and put through its paces, how can it be trusted?" she said.
Lynch added that it was often in particularly gruesome cases like this one, or in situations where good defense was unaffordable, that bold precedent was set.
Others previously concerned with Green's methods — including Jenny S. Cheung, supervising attorney of the DNA Unit of The Legal Aid Society; her colleague, DNA resource staff attorney Martha Saunders; and New York Innocence Project forensic science policy specialist Tebah Browne — declined to comment again on the case.
Following Mazzei's decision, Heuermann's attorneys said that if their client is convicted, he would appeal the use of the DNA evidence. In previous filings, they argued the science wasn't ready.
Suffolk County District Attorney Ray Tierney said in an email to Law360 that he looks forward to proving the allegations against Heuermann in court and was pleased with the court's decision.
Proponents of Green's work also agreed with Justice Mazzei's order, saying just because something is new, doesn't mean it's automatically faulty.
Teresa Vreeland, vice president of forensic genealogy services at Bode Technology, a private lab that performs whole genome sequencing, said she wasn't surprised by the ruling.
"I think it's scientifically sound and that's where the forensic community is moving," she said.
"Laboratory wise, it's something that's been possible, but seeing it work its way through the courts and the education process is exciting and nice to see," Vreeland added.
Vreeland said that at the time New York was looking to analyze the hairs from the Gilgo Beach case in 2020, Astrea and Green were likely their only hope.
Green, who is a pioneer in his field, is often working in uncharted territory, but in order to innovate, a path must be blazed, he said.
"When you are doing something that hasn't been done, there are no rules or guidance," Green said of his early work identifying Edith Cook.
In 2019, the U.S. Department of Justice authored guidelines for forensic genetic genealogy, which similarly relies on SNP data, and Green called it helpful.
Forensic genetic genealogy, used in the Golden State Killer case, has historically been used to pinpoint suspects, with identification later getting confirmed using traditional short tandem repeat DNA matching. When it comes to rootless hairs, like in Gilgo, STR profiles aren't possible, prosecutors said.
With the kind of sequencing Green does, in addition to finding matches using challenging samples, DNA submitted by a long-dead grandmother can be used to identify a descendant she never met.
The possibilities for identification are vast, Green said, envisioning a future where criminals may be almost immediately apprehended. Former Sacramento DA Schubert said she imagined eliminating the word "serial" from criminal vocabulary using Green's techniques.
This high-tech future deeply concerns the EFF's Lynch, who said there were many ways a person's DNA might end up at a crime scene, as Heuermann's case itself shows. Suppose his family didn't have strong alibis, but were uninvolved — how would they prove their innocence, Lynch asked, especially if DNA technology becomes so advanced it can pick up minute samples.
For Green, police work was not his purview. He said he understood certain privacy concerns and had some himself.
"We try to do it in a way that is a net positive for society," he said, recalling other cases he worked on, like the murder of Daralyn Johnson, who was killed in Idaho by David Allen Dalrymple in 1982 while walking to school. That case led to the development of the IBDGem software, according to Green's testimony in the Gilgo Beach case.
"You can't meet the parents of a 9-year-old girl who is raped and murdered in a ditch, and then that is solved, you can't meet them and think that there is not use and justice in this," Green said.
--Editing by Kelly Duncan.
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