In a major development in the Gilgo Beach serial killer case, a judge has ruled that nuclear DNA evidence will be permitted in the prosecution of Rex Heuermann — a decision prosecutors are calling a landmark victory.

The ruling allows a relatively new forensic technique to be used in a New York courtroom for the first time to link a suspect to a crime scene. While the science behind nuclear DNA analysis isn’t new, its application in such a fragmented and complex case is unprecedented in the state.

What Is Nuclear DNA — And Why Does It Matter? Nuclear DNA is inherited from both parents and is unique to each individual, making it significantly more precise than mitochondrial DNA, which has been used in past cases like this one. Mitochondrial DNA, inherited only from the mother, can be shared among relatives and is typically used because it exists in more copies per cell and can survive longer in degraded samples.

However, in this case, forensic experts analyzed extremely small and fragmented pieces of nuclear DNA. According to Professor Nathan Lents, of John Jay College of Criminal Justice, this method allowed scientists to examine tiny genetic markers scattered across the genome — a process that has been used to identify human remains but not previously to connect a suspect to a crime in New York state.

"Nuclear DNA is more precise," said Lents. "What’s new about this is because it was so fragmented, we had to look at the tiny markers all over the genome. The application of that against a defendant is new. So the technology isn’t new, but its use in the forensic setting is what’s new here."

A Turning Point — Or Another Legal Battle Ahead? The defense team for Heuermann is not backing down. Attorneys have already filed a motion to block the nuclear DNA evidence from being used at trial, potentially setting the stage for another courtroom battle over the admissibility of cutting-edge forensic science.

Heuermann, an architect from Massapequa Park, stands accused in connection with multiple murders in the infamous Gilgo Beach case, which remained unsolved for more than a decade.