The county prosecutor leading the investigation into the decade-old murders of mostly women along Ocean Parkway in Gilgo Beach, N.Y., said new advances in DNA technology in part helped break the case.
Suffolk County District Attorney Raymond Tierney told Fox News on Friday that suspect Rex Heuermann's arrest came after five "hairs of significance" from four victims were able to be further studied thanks to mitochondrial DNA technology.
The bodies found at Gilgo Beach, several miles east of the better-known Jones Beach, had been exposed to weather for so long that the DNA was too degraded to be properly analyzed using standard nuclear DNA technology.
"When people think of DNA, it's nuclear DNA that's the traditional DNA analysis that is done. But as the science advanced and although the hairs were [too] degraded for nuclear DNA, we were able to use them for mitochondrial DNA," Tierney said,
"So we were able to use that technology, but we still had to develop a suspect. And that's where the phone evidence and the evidence with regard to the car and some of [Heuermann's] other activities came in."
On "Special Report," Tierney discussed the cellular coverage "box" that helped lead to Heuermann's arrest.
The suspect purportedly used burner phones, and New York authorities were able to use a perimeter of cell phone ping locations that matched calls made to some of the victims, according to the UK Guardian.
LI MURDERS SUSPECT REX HEUERMANN ARRESTED; UPDATES
"The FBI and other phone analysts are really skilled in what they can do," Tierney said. "So they could really analyze phone records and really isolate location areas where suspicious activity occurs. And that really allows you to capture or identify suspects."
Heuermann lived in Massapequa Park, just across the Nassau County line from Gilgo Beach, and worked at an architectural firm in Manhattan he also owned.
He is charged with three counts of first-degree murder and three counts of second-degree murder in connection with the murders of Maureen Brainard-Barnes, Melissa Barthelemy, Megan Waterman and Amber Costello.
Tierney called Friday a "watershed day" due to not only Heuermann's arrest, but also the execution of several other search warrants he hopes will further lead to justice and closure.
Tierney and Suffolk County Police Commissioner Rodney Harrison – a recent chief of police for the NYPD – held a press conference in Yaphank shortly after Heuermann was arraigned in neighboring Shirley.
A bail application revealed that Heuermann was arrested with additional help of DNA from a discarded pizza box.
