During a hearing Tuesday, accused Gilgo Beach serial killer Rex Heuermann’s defense team called their first expert witness, but the witness’s qualifications were reportedly met with skepticism by the prosecution.

According to LI Press, during the Frye hearing at the Suffolk County Court in Riverhead, the defense and prosecution continued to debate the scientific validity of the DNA evidence. The defense questioned the evidence linking Heuermann to six of the seven murders he’s charged with.

The defense introduced Nathaniel Adams as their first expert witness, a systems engineer at Forensic BioInformatics, Inc.

Adams said he has a Bachelor’s degree and is working toward a Master’s degree in Computer Science at Wright State University, having completed his coursework but not his thesis. Defense attorney Danielle Coysh addressed his qualifications ahead of the prosecution’s cross-examination.

Adams testified that the IDBGEM program, used to detect DNA in the case, is “unreliable” due to its tendency to misread genotype data. The software, which has been updated multiple times, was used to link Heuermann to six of the seven sex workers murdered and dumped on Gilgo Beqch in Long Island over a span of more than 30 years.

“It’s unreliable,” Adams said.  “The software has been updated multiple times since the DNA in this case has been tested.”

Adams disclosed that there have been 65 updates to the software, and newer versions have been released since June 2020, when Heuermann’s and his family’s DNA was tested, The New York Post reports.

Suffolk County District Attorney Ray Tierney questioned Adams expertise, arguing that Adams’ findings in other cases had been “inadmissible.”

“You’ve been in school for 10 years and have only obtained a bachelor’s degree in all this time?” Tierney asked. “You’re supposed to be an expert, but you don’t even know who your adviser was or if you graduated summa cum laude or not.”

As CrimeOnline previously reported, investigators tied Heuermann to the victims through hair evidence. The victims, all sex workers, vanished between 1993 and 2010.

The deaths of Valerie Mack, 24; Taylor, 20; Megan Waterman, 22; Melissa Barthelemy, 24; Maureen Brainard-Barnes, 25; Sandra Costilla, 28; and Amber Lynn Costello, 27, remained unsolved until the case was reopened in 2022.

Polive arrested Heuremann in July 2023 for three murders and later connected him to the other murders through DNA.

Meanwhile, at a Wednesday press conference, defense attorney Michael Brown stated that Adams performed well, and the defense has not yet decided whether to present another witness at the next hearing, scheduled for July 17.

Brown also stated that the trial is unlikely to begin before 2026.

Check back for updates.

[Feature Photo: Rex Heuermann/Suffolk County Sheriff’s Office via AP]