Gilgo Beach killings: Cutting-edge DNA technology can be used to solve other cold cases, experts say

A court ruling earlier this week allowing cutting-edge DNA evidence in the trial of alleged Gilgo Beach serial killer Rex A. Heuermann could crack open many vexing cold cases on Long Island and across New York State, experts told Newsday.

The technology that prosecutors say linked Heuermann to six of the seven alleged victims is "a game changer," said Nathan Lents, a professor of biology at John Jay College of Criminal Justice in Manhattan. 

"There is probably biological evidence sitting in evidence lockers around the country that was never tested because it was too old or too minuscule for the technology of the time," Lents said. "But with the advances in DNA sequencing, we may be able to get a profile from that evidence and it could break the case."

Suffolk County District Attorney Ray Tierney said after the judge's ruling that investigators would examine whether it could be used to help solve the hundreds of other cold cases in Suffolk.

"When dealing with cold cases, one of the first questions we ask is: Can new technology help us to gather more information?" Tierney said. "So this is going to be a consideration on each of those cold cases. Sometimes it's appropriate and other times it's not, so we'll just have to take it on a case-by-case basis."

The district attorney's office opened its first Cold Case Unit last year, Newsday reported, in an effort to prosecute the approximately 300 cold case homicides since 1965.

Tierney said the new technology could be used to advance those cases. 

"We've got a number of cases that we're looking at," Tierney said. "We look at those cases individually. And obviously, this is another tool in our tool box."

Supreme Court Justice Timothy Mazzei on Wednesday ruled the DNA analysis performed by Astrea Forensics, in Santa Cruz, California, would be admissible at Heuermann's upcoming trial.

Mazzei's ruling came after a hearing in Suffolk County Court in Riverhead to determine whether the lab's methods were generally accepted in the scientific community, which is the standard for admissibility in New York State.

Heuermann's defense team has filed a new motion arguing Astrea's work on the case violates New York State public health law because the lab is not licensed in the state. The judge is scheduled to rule on that argument later this month. 

Not guilty pleas

Heuermann, 61, has pleaded not guilty to murder charges in the deaths of seven women from 1993 to 2010: Melissa Barthelemy, Amber Lynn Costello, Megan Waterman, Maureen Brainard-Barnes, Jessica Taylor, Valerie Mack and Sandra Costilla.

Using the DNA technology on nine rootless hairs found with the remains of six of the victims, prosecutors say they linked Heuermann to the killings.

The hairs, according to the analysis, likely belonged to either Heuermann, his now-ex-wife Asa Ellerup or their daughter, Victoria Heuermann. Prosecutors have said there's no indication Heuermann's ex-wife or daughter had any knowledge of the alleged killings. 

Astrea's lab extracts DNA from rootless hair samples, which have fragmented DNA that is difficult to test using standard DNA analysis. The lab conducts whole genome sequencing on the DNA and then, using a special software which develops likelihood ratios, compares it to a sample from a known subject in order to establish the likelihood of the source.

Whole genome testing is not new and has been used extensively in medical, ancestry and genetics research fields, experts said, though it was more recently used in forensics. 

Heuermann's defense attorneys, including lead attorney Michael J. Brown and co-counsel Danielle Coysh, have questioned Astrea's methods. Brown has derided them as "magic." 

Tierney said the DNA evidence is part of the evidence prosecutors say links Heuermann to the killings, including cellphone evidence and what prosecutors said was a "planning document" on how to kill and get away with it found on a hard drive in Heuermann's basement. 

Julie Burrill, an affiliate researcher at Stony Brook University, reviewed the judge's ruling in the Heuermann case at Newsday's request.

"I agree that the underlining principles behind it are probably sound, whether that makes it entirely appropriate to apply in this way in this case, is a sort of different question," she said.

DNA and juries

Burrill said the intricacies of DNA testing tend to get lost on juries.

"The way that DNA gets presented in court, a jury is most likely to hear, 'oh, the DNA matches,' that means it’s this persons and nobody else’s in the entire world. End of story. Because that’s generally what we think when we hear DNA," she said.

Lents, who was also provided the judge's decision for review, said both the legal and scientific processes appeared to work. 

"They have every right to challenge this new approach," Lents said. "We have to remember that the defense attorneys are not just defending Rex Heuermann. They are defending all of us by forcing government prosecutors to prove the accuracy of this technology under strict scrutiny."

And Astrea's results linking Heuermann are "pretty convincing," he added.

"Even with the most conservative possible approach toward calculating the likelihood ratios, the match of the SNP profile from these rootless hairs to Rex Heuermann is still pretty convincing," Lents said. "But the defense will be allowed to call experts to challenge the match and, again, that’s a good thing. The process is working."

By Nicole Fuller

nicole.fuller@newsday.com@NicoleFuller

Nicole Fuller is Newsday's senior criminal justice reporter. She began working at Newsday in 2012 and previously covered local government.