Judge allows cutting-edge DNA technology in case against suspected Gilgo Beach serial killer

Evidence derived from cutting-edge DNA technology that prosecutors say points directly at Rex Heuermann being the Gilgo Beach serial killer will be admissible at his trial, a Suffolk County judge ruled Wednesday.

The decision by Suffolk County Supreme Court Judge Timothy Mazzei is an important win for prosecutors and a blow for the defense team that challenged the validity of this type of technology that specializes in extracting nuclear DNA from damaged or hard-to-get samples, such as rootless hair.

It was these types of individual stray hairs that were found on six of the seven victims prosecutors say Heuermann killed, according to court records. Heuermann is charged with murder in the deaths of the seven women and has pleaded not guilty.

Heuermann’s defense attorney Michael Brown had argued the DNA technology, known as whole genome sequencing, has not yet been widely accepted by the scientific community and therefore shouldn’t be permitted. He said he plans to argue the validity of the technology before a jury.

Meanwhile, prosecutors have argued this type of DNA extraction has been used by local law enforcement, the FBI and even defense attorneys elsewhere in the country, according to court records.

“The science was on our side and that’s why we won,” Suffolk County District Attorney Raymond Tierney said after the court deemed the technology admissible.

Tierney thanked his team and expert witnesses, saying he is “very thankful that this result is behind us.”

Heuermann is due back in court for a status conference hearing September 23. “We’re fast reaching the pretrial stage and we’re hurdling towards the trial stage,” the district attorney said.

A full genetic ‘blueprint’

The DNA analysis in the case was conducted by California-based Astrea Forensics, a company that specializes in whole genome sequencing.

Whole genome sequencing is “a method that attempts to read nearly all of a person’s DNA, covering the entire genetic code of about 3 billion bases,” or letters, said Daniele Podini, an associate professor at George Washington University.

The key difference, Podini said, is conventional testing provides a limited DNA “fingerprint,” like a barcode on a supermarket product, while whole genome sequencing (WGS) offers a full genetic “blueprint” with much more detailed insights.

Though the type of analysis has “not yet been subject to an admissibility hearing in the State of New York,” prosecutors said in their argument to the judge earlier this year, the technique is commonly used across numerous scientific and forensic fields, including virology, health care and criminal justice — and by law enforcement, prosecutors and defense attorneys.

New technologies are always up for examination before becoming routine, said Nathan Lents, a professor of biology at the City University of New York’s John Jay College of Criminal Justice.

“Forensic methods are subject to intense legal scrutiny before they are accepted as common practice, and that’s what we are seeing here,” Lents said. “This is the normal way that new techniques are introduced into the legal forensic toolkit, in test cases with a great deal of scrutiny and expert testimony.”

“This decision and this litigation marks a significant step in forensic DNA analysis,” Tierney said following the judge’s ruling Wednesday. “This is where we’re headed in the science.”

CNN’s Mark Morales reported from Riverhead and Michelle Watson reported from New York. CNN’s Rebekah Riess wrote and reported from Atlanta.

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