The DNA software used to connect Rex Heuermann to the Gilgo Beach murders was reportedly unreliable, requiring multiple updates after it linked him to the crimes, a defense expert testified Tuesday.

Nathaniel Adams, a biotech specialist on Heuermann’s defense team, remarked in court that the IDBGEM program often misreads genotype data, which was key in tying the suspect to six of seven victims—sex workers murdered on Long Island over three decades.

“It’s unreliable,” said Adams, a 27-year-old systems engineer for Forensic Bioinformatics in Ohio. “The software has been updated several times since the DNA testing in this case.”

5

He emphasized that bugs in the software necessitate a detailed analysis to prevent mistakes that could cause miscarriages of justice.

Suffolk County District Attorney Ray Tierney challenged Adams’ expertise, noting that much of his testimony in other cases was considered inadmissible and questioning his qualifications.

“You’ve been in school for ten years and only earned a bachelor’s degree? You’re supposed to be an expert, but you don’t even know your adviser or your academic honors?” Tierney questioned on the stand.

DNA evidence is pivotal in linking Heuermann directly to the murders.

5

Authorities have conducted two search warrants at Heuermann’s Massapequa Park residence, digging up the backyard and examining a basement “kill room,” though no physical evidence has been disclosed.

Investigators did find a disturbing file—described as a “how-to” guide and notes providing tips for the murders.

The case has garnered national attention and is the focus of a newly released three-part Peacock documentary featuring rare interviews with Heuermann’s family.