Though Justice Timothy P. Mazzei did not announce his decision in open court before Heuermann and his former spouse, Asa Ellerup, who was also in attendance, he commended both sides, saying that their briefs, "though not brief ... were truly excellent."
In his 29-page opinion, Justice Mazzei concluded that Astrea Forensics, the lab hired to analyze rootless hairs found on the bodies of victims, used a method "generally accepted as reliable within the scientific community."
His decision was based not only on expert testimony, but also on numerous peer-reviewed articles submitted by prosecutors, he wrote. Justice Mazzei was also influenced by the fact that Astrea's work had been used in cases in other jurisdictions, including in Idaho and California, though it had not — until now — cleared the standards established by the 1923 U.S. Supreme Court decision in Frye v. U.S.
, on which New York relies.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.
As a result, they turned to Richard "Ed" Green, whose company Astrea Forensics used "shotgun sequencing" to analyze the DNA fragments present in the hairs to reveal as much as possible of the genome of the person the hair came from. The company then used a computer program called IBDGem to compare the genetic material found in the hairs with genetic material taken from the suspect, prosecutors said.
Justice Mazzei wrote Wednesday that neither of the defense's two expert witnesses had controverted the use of whole genome sequencing. And while those experts had attacked the use of the IBDGem software as unproven, the judge said he agreed with Green instead.
"While IBDGem is a relatively new software system, the principles used within it, which are behind the math used and data collected, are accepted as reliable in the scientific community," the judge wrote.
District Attorney Raymond Tierney told reporters after his court appearance, "The science was on our side and that's why we won."
Heuermann's team had opposed the admission of Astrea's analysis, calling it "magic" — a phrase again repeated by his defense attorney, Michael J. Brown, following the court's decision.
"Those magic numbers are going to be put before a jury," Brown said, referencing the likelihood ratios developed by Astrea, which allegedly confirm that hairs found on the serial killer's victims came from Heuermann and people he lived with.
Heuermann, who has pled not guilty to killing seven women, is an architect who worked in New York City 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.
At a press conference following his Suffolk County Court appearance, Brown lamented the court's decision. He said that if Heuermann is ultimately found guilty, this DNA evidence decision will likely be appealed.
For now, Heuermann is again challenging the admissibility of the DNA evidence, arguing in a motion filed Wednesday that Astrea is not accredited in New York, in violation of state health code, meaning that anything the lab offers is "patently unreliable" and should be precluded, the filing says.
Tierney said he was not too concerned with Heuermann's latest filing, noting that the state ended up working with Astrea through the FBI. Instead, he was satisfied that the DNA evidence, which he said was just one piece of the case against Heuermann, could be presented to a jury.
"This decision and this litigation marks a significant step in forensic DNA analysis," he said, noting that as it had helped in the Gilgo Beach case, where victims had been killed between 1993 and 2011, it could help in other cold cases.
"We've got a number of cases that we are looking at and obviously this is another tool in our toolbox," Tierney said.
Justice Mazzei said he would make a decision on Heuermann's latest motion on Sept. 23. Both Tierney and Brown said there was no talk of a plea deal. No trial date has been set in the case.
The state is represented by Andrew Lee, Nicholas J. Santomartino, Michelle Haddad, Lawrence Opisso, Meaghan Powers and Raymond Tierney of the Suffolk County District Attorney's Office.
Heuermann is represented by Michael J. Brown of Michael J. Brown PC, Danielle Coysh of the Law Office of Danielle Coysh PLLC and Sabato Caponi of the Law Office of Sabato Caponi.
The case is The People of the State of New York v. Rex A. Heuermann, indictment number 73544-24, in the Supreme Court of the State of New York, Suffolk County.
--Editing by Emily Kokoll and Daniel King.
Update: This story has been updated with additional details.
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