Gilgo Beach killings: All 7 murder cases against accused serial killer Rex Heuermann will be tried together, judge rules

Accused Gilgo Beach serial killer Rex A. Heuermann will face a single trial for all seven alleged killings, a Suffolk judge ruled Tuesday.

State Supreme Court Justice Timothy Mazzei informed attorneys for both sides during a brief conference in Riverhead that he ruled against a defense request to split the cases into multiple trials.

Mazzei also determined for the second time that nuclear DNA evidence in the case will be admissible at trial, denying a final push by Heuermann’s defense to exclude the DNA because an outside laboratory lacked New York State Department of Health permits.

Suffolk County District Attorney Ray Tierney described the judge’s decisions as victories for his office, which he said properly joined each of the killings in a single superseding indictment because they are "inextricably interwoven." Tierney noted that an alleged planning document for the killings investigators found Heuermann once maintained was a considerable factor in Mazzei’s decision to keep the cases joined together.

"That planning document talks about ... murders that had occurred, that are about to occur and that are going to occur in the future," Tierney said of the deleted file investigators were able to recover off a device seized from Heuermann's Massapequa Park home. "When you have all of that evidence, and you take into consideration factors of judicial economy, I think that it's fairly obvious that this case was properly joined, should not be severed, and it's proper to go forward in one trial."

'Overlapping evidence'

Mazzei wrote in his decision that the evidence in the first three killings charged against Heuermann, which the defense sought to separate from the other four, would be "material and admissible" at trial in the remaining cases, according to a copy of the decision.

"Joinder was proper based on the overlapping evidence, the similarity in the manner in which the crimes against all of the complainants was committed, to prove the identity, pattern, motive and modus operandi of the defendant," Mazzei wrote.

A defense motion filed in January argued that a "substantial disparity" exists between the evidence in the first indictment — charging Heuermann with first- and second-degree murder in the killings of Melissa Barthelemy, Amber Lynn Costello and Megan Waterman — and the allegations in three superseding indictments, which could lead to an improper conviction based on "cumulative effect."

The defense filing made several additional arguments for why the killings of Maureen Brainard-Barnes, Jessica Taylor, Valerie Mack and Sandra Costilla cannot be lawfully tried alongside the first three charged killings and should also be tried separately from each other, including the timing of their deaths spanning nearly 17 years, varying methodologies used in the killings and the different locations where their bodies were found, which includes Manorville and North Sea.

Areas to explore

Heuermann defense attorney Michael J. Brown, of Central Islip, expressed disappointment in the judge’s decision but said the defense still has other areas to explore before the case heads to trial.

"The judge ruled against us," Brown said outside the courtroom. "We don't like the decision, we don't agree with the decision, but in our system, we accept the decision and we move forward. That's how our system works."

Brown said the defense now intends to file motions related to search warrants and grand jury presentations in the case.

"We don't believe that there's a reasonable cause, a probable cause, that was presented to the grand jury on two specific victims at a minimum," Brown said, declining to name which two victims he was referring to.

Mazzei, who previously indicated a trial date could be set this week, instead set a Jan. 13 deadline for those defense motions to be filed.

"There’s a lot of discovery involved in this, so I’m going to give you extra time," Mazzei assured Brown from the bench.

Plea deal speculation

Both sides continued to reject the idea that the case could end in a guilty plea before ever reaching trial.

Robert Macedonio, who appeared at Tuesday’s hearing as the attorney for Heuermann’s ex-wife, Asa Ellerup, and daughter Victoria Heuermann, said talks of a plea are "speculation at this point." Macedonio said there’s really nothing Suffolk prosecutors could offer Heuermann in terms of a deal, but that a plea would spare the families of the victims and Heuermann’s own family from a trial. Macedonio made the plea deal remarks while answering a question from a reporter about the possibility of a plea.

Brown said talks of a plea are "not true."

Heuermann, 62, a Manhattan architect, was first arrested in July 2023 and has pleaded not guilty to each of the killings, in a cold case that had haunted investigators for years after the remains of a missing woman were first discovered near Gilgo Beach in December 2010.