In a ruling that could reshape the future of forensic science, a New York state judge declared Wednesday that DNA evidence tying accused Gilgo Beach serial killer Rex Heuermann to victims found along Long Island’s shores can be shown to a jury. It is the first time whole genome sequencing has cleared New York’s rigorous legal admissibility standards.

Justice Timothy P. Mazzei of Suffolk County issued a 29-page opinion affirming that Astrea Forensics, the lab hired by prosecutors, used methods “generally accepted as reliable within the scientific community.”

The Science Behind the Evidence

Investigators had only five rootless hairs from the victims—too degraded for standard DNA tests. Instead, prosecutors turned to Astrea Forensics, which applied “shotgun sequencing” to analyze fragmented genetic material. Using a program called IBDGem, they compared that DNA to Heuermann’s.

Defense experts attacked IBDGem as “unproven,” but Mazzei sided with prosecutors, writing that while the software is relatively new, the underlying mathematics and principles are widely accepted.

District Attorney Raymond Tierney hailed the ruling: “The science was on our side and that’s why we won.”

Defense Pushback

Heuermann’s attorney, Michael J. Brown, dismissed the evidence as “magic,” vowing to appeal if his client is convicted. “Those magic numbers are going to be put before a jury,” he said.

Heuermann, a Massapequa architect, has pleaded not guilty to murdering seven women between 1993 and 2011. Victims were discovered in horrific conditions—some dismembered—along the Gilgo Beach corridor.

The case gained traction after an eyewitness linked Heuermann’s vehicle to one of the victims, Amber Costello, sparking the investigation that led to his 2023 arrest.

Wider Forensic Implications

Prosecutors argue this decision doesn’t just impact the DNA Gilgo Beach Case, but may revolutionize cold case investigations nationwide. Tierney confirmed Astrea had worked with the FBI and stressed this DNA is “just one piece” of the state’s case.

“This marks a significant step in forensic DNA analysis,” Tierney said. “It opens doors for countless other cold cases.”

What’s Next

Heuermann’s defense filed a fresh motion Wednesday, claiming Astrea isn’t accredited under New York law, rendering its evidence “patently unreliable.” Judge Mazzei said he will rule on that argument by Sept. 23.

No trial date has been set, and both sides confirmed no plea deal is on the table.

The state’s case is being handled by Andrew Lee, Nicholas J. Santomartino, Michelle Haddad, Lawrence Opisso, Meaghan Powers, and Raymond Tierney. Heuermann’s defense team includes Michael J. Brown, Danielle Coysh, and Sabato Caponi.