Quantcast

Judge grows weary as Gilgo Beach DNA hearing winds down

Judge
Alleged serial killer Rex A. Heuermann is escorted into Judge Tim Mazzei’s courtroom at Suffolk County Court in Riverhead for a frye hearing on Thursday, July 17, 2025.
James Carbone/Newsday via Pool

The bench is above reproach – but not above frustration.

As the hearing over the admissibility of DNA evidence in suspected Gilgo Beach serial killer Rex Heuermann’s case nears its end, Suffolk County Court Judge Timothy Mazzei has grown increasingly impatient. The hearing, known as a Frye hearing, began in March, and it’s set to determine whether the nuclear DNA that links Heuermann to six of his seven alleged victims will be admissible in court.

Thursday’s witness was Dr. Dan Krane, a professor of biological sciences at Wright State University and the president of Forensic Bioinformatic Services, a consulting firm – which also employs Nathan Adams. He was the defense’s last witness.

Judge
Judge Timothy Mazzei presides over status conference for alleged Gilgo serial killer Rex Heuermann, at Suffolk County Court in Riverhead on Tuesday, Feb. 25, 2025. (James Carbone/Newsday via Pool)

A frustrated judge

The hearing started at 11:45 a.m. due to Krane’s flight issues, rather than the usual 9:30 a.m. Mazzei called an hour recess for lunch at 1 p.m., and when Krane wasn’t immediately in the courtroom, expressed his anger.

“Where is your witness? What part of 2 o’clock don’t you guys understand?” Mazzei said to defense attorneys Danielle Coysh and Michael Brown. “We’re already behind schedule. Get him the hell in here! He’s going to be surprised when I see him next week.”

When Suffolk County District Attorney Ray Tierney cross-examined Krane, he requested yes or no answers to questions, to which Krane did not acquiesce, trying to give longer answers, prompting Mazzei to shout at him, “Just answer the question!”

One of Tierney’s questions drew laughs from the gallery – and from Krane.

“It’s not funny,” Mazzei said, admonishing Krane. “Answer the question.”

Another question from Tierney prompted Krane to say “Can I draw your attention –” but he was abruptly cut off by the judge.

“No, you can answer the question,” Mazzei said. “Can you answer yes or no?”

In another exchange, where Krane was asked to discuss if he knew people who had done peer review of a genetics-related paper, he was cut off by Mazzei while pondering if he did.

“Doctor, you do not know any of these people,” Mazzei said.

The defense examined Krane to open Thursday’s hearing. He was then cross examined by the prosecution, and the defense examined him again. When the prosecution opted to rest, Mazzei made his feelings on the length of the hearing known.

“God bless you,” Mazzei said to the prosecution.

Judge
Dr. Dan Krane, center, an expert witness for the defense in suspected Gilgo Beach serial killer Rex Heuermann’s Frye hearing. (Michael Malaszczyk)

Witness casts doubt on nuclear DNA

Without the nuclear DNA evidence, Heuermann is still linked to several victims through mitochondrial DNA. However, mitochondrial DNA makes Heuermann part of a small population that could be contributors to hair found on victims, while the nuclear DNA points directly at Heuermann with a statistical probability that rules out anyone else.

The nuclear DNA testing was conducted by California-based Astrea Labs, which uses a program called IBDGem. IBDGem has not yet been used in any case in New York State.

Krane said it is novel science and not fully accepted in the scientific community.

“We’ve had one paper that describes what IBDGem does,” Krane said. “It’s the new kid on the block.”

Krane said that a program like IBDGem is paradigm shifting.

Prosecution casts doubt on witness credibility

When Tierney cross-examined Krane, his goal was clear: cast doubt on both witnesses called by the defense.

The defense’s first witness, Nathaniel Adams, has not yet completed his master’s degree. Additionally, Adams works for Forensic Bioinformatics. Tierney pressed Krane on the issue of those witnesses being a conflict of interest, as they are employer and employee. Additionally, Krane is on Adams’s master’s thesis committee.

Tierney’s keynote moment was finding a paper Krane himself had written in 2003, where Krane wrote that someone who does not have a master’s degree should not be considered an expert in their field.

Tierney also pointed out Krane’s history of being called for DNA hearings as an expert witness and, typically, as a skeptic of new DNA technology. He pointed out how Krane has testified against the admissibility of both RFLP and PCR DNA testing, both of which are now widely accepted in the scientific community.

 What’s next in the Frye hearing?

The hearing wrapped up around 4:30 p.m. Friday. Mazzei set the next hearing for Tuesday, July 22, but informed Heuermann he would not need to appear in court as it is just for paperwork. The defense will determine by then if it will call another witness or rest.

“Understood,” Heuermann said to Mazzei.

Tierney did not speak to reporters following the hearing. Brown expressed how he did not take Mazzei’s words personally and praised Mazzei as a judge. Brown continues to assert Heuermann’s innocence.

Heuermann is charged with the murders of Melissa Barthelemy, Amber Lynn Costello, Maureen Brainard-Barnes, Megan Waterman, Valerie Mack, Jessica Taylor, and Sandra Costilla between 1993 and 2010. He has pleaded not guilty to all charges.