DNA ruling gives Suffolk prosecutors a win in Rex Heuermann Gilgo Beach case
Judge Mazzei allows use of high-tech DNA evidence in a single trial for seven killings; defense had sought separate trials
A Suffolk County judge on Tuesday allowed prosecutors to use high‑tech DNA evidence against Rex Heuermann in the Gilgo Beach killings, marking a major win for the district attorney’s office as the case moves toward a single trial for seven murders.
Judge Tim Mazzei ruled that genetic evidence gathered from a laboratory analysis can be admitted at trial, a decision that consolidates the case against the 61-year-old accused serial killer. Heuermann has been held without bail since his arrest in July 2023. The prosecution’s case has largely hinged on DNA matches tied to seven victims found along a desolate stretch of Long Island between 1993 and 2010. The women named by investigators are Valerie Mack, 24; Melissa Taylor, 20; Megan Waterman, 22; Melissa Barthelemy, 24; Maureen Brainard-Barnes, 25; Sandra Costilla, 28; and Amber Lynn Costello, 27.
The defense, led by attorney Michael Brown, had challenged the DNA evidence, arguing that the lab responsible for testing—Astrea Labs—should not be allowed to contribute to the case because its licensing status in New York was uncertain and the methods could run afoul of state health laws. Brown had also sought to separate the murders into individual trials, a request Mazzei rejected as the judge kept the seven cases consolidated for a single trial. Brown has called the DNA evidence “magic” and has accused prosecutors of relying on an unproven technology.
Prosecutors, led by District Attorney Ray Tierney, say the DNA presentation will be expansive. Tierney has signaled the state will call more than 100 witnesses from 15 states and introduce millions of documents as part of the evidentiary record. The state contends that the Astrea Labs testing—employing advanced techniques to salvage damaged genetic material—represents a milestone in New York forensic practice, marking the first time such damaged samples have been used in a state courtroom. The defense counters that the volume and scope of the evidence could overwhelm the defense and complicate the trial process.
The Gilgo Beach investigation was reopened after Rodney Harrison became Suffolk County police commissioner, a move that unlocked new leads and ultimately resulted in Heuermann’s arrest. The murders have remained unsolved for years, with the evidence that ties Heuermann to the victims forming the backbone of the government’s forthcoming presentation. The victims’ families have waited years for answers, for a case that has drawn national attention and scrutiny over the policing and investigative decisions that preceded the 2010s.
The decision to allow the DNA evidence to be used in a single, consolidated trial underscores the centrality of forensics to the government’s case. If the trial proceeds as planned, jurors will evaluate a bulky evidentiary record, including genetic matches, lab procedures, and thousands of documents, as they determine Heuermann’s guilt or innocence across the seven counts.
The case remains a focal point in the ongoing debate over the use of cutting-edge biotechnology in criminal prosecutions, as prosecutors prepare for what is likely to be a lengthy and highly technical trial. While Mazzei’s ruling narrows the defense’s argument against the DNA evidence, Brown has indicated that he will continue to challenge the lab’s licensing and the admissibility of specific test results as the trial unfolds.
Amid the procedural debates, prosecutors have laid out a sweeping plan for testimony and documentation. Tierney has said the state will present a broad array of witnesses from multiple jurisdictions, and the volume of materials associated with the case is expected to be among the largest in Suffolk County history. The defense, for its part, has stressed the potential for pretrial and trial motions to shape the evidentiary landscape, including challenges to the DNA chain of custody and the handling of laboratory data.
The seven victims were identified as part of the district attorney’s effort to close a long-running chapter in Long Island crime history. While the ruling marks a significant procedural victory for prosecutors, it does not resolve the broader questions surrounding the case or the long timeline that kept the Gilgo Beach killings in the public eye for more than two decades. As the trial timetable begins to take shape, families and communities will continue to monitor developments that could determine whether justice is achieved for the women who were murdered and for the public at large.
