Gilgo Beach killings: Rex Heuermann was 'extremely familiar' with Ocean Parkway, where 6 of 7 alleged victims were buried, court papers say

Alleged Gilgo Beach serial killer Rex A. Heuermann worked at Jones Beach for about three years when he was in his early 20s and became "extremely familiar with Ocean Parkway," which was the burial site for six of the seven women Heuermann is charged with killing, Suffolk prosecutors said Tuesday in court documents.

"The investigation to date has established the defendant worked at Jones Beach from approximately 1981-1984," prosecutors said in the court documents. "Part of defendant’s work at the beach entailed the defendant getting on All-Terrain Vehicle and going from field to field to ensure beachgoers were off the property once the beach was closed, a role that made the defendant extremely familiar with Ocean Parkway at night."

The new details of Heuermann's alleged familiarity with the site appears in a 34-page document from prosecutors opposing a defense motion that seeks to separate the charges into multiple trials. Prosecutors are advocating for Heuermann to be prosecuted in a single trial that includes all the cases.

"This evidence, of defendant’s connection to the shared burial site of six of the seven victims, is another overlapping aspect of the defendant’s modus operandi, which provided the defendant with the motive, means, and opportunity to commit the charged crimes," the document added.

The prosecution's written opposition to the defense motion to break up the cases came as Heuermann appeared in a Riverhead courtroom Tuesday.

Heuermann, 61, of Massapequa Park, has pleaded not guilty to first- and second-degree murder in the killings of Melissa Barthelemy, Amber Lynn Costello, Megan Waterman, Maureen Brainard-Barnes, Jessica Taylor, Valerie Mack and Sandra Costilla.

Suffolk Supreme Court Justice Timothy Mazzei on Tuesday set a March 12 deadline for the defense to reply to the prosecution's opposition to trying some of the cases separately.

Mazzei said he had intended to set a date for pretrial hearings related to the admissibility of DNA evidence on Tuesday, but the defense is still waiting for a hard drive with new discovery information. The prosecution said that should be received by the defense by the end of the week.

Suffolk County District Attorney RayTierney addressed journalists after Heuermann's brief court appearance.

"The theory of our case is this defendant is a serial killer who meticulously and methodically hunted down and murdered seven women," Tierney said. "That is our case."

Lead Heuermann defense attorney Michael J. Brown, speaking after court Tuesday, laid out why the defense thinks the case should be divided into five trials.

"They have nothing to do with each other in the sense of the location of where the bodies were found, the type of murder that was committed, the evidence that they have," Brown said. "But in essence, what the prosecutor is doing is they throw everything into the grand jury, and they try to throw as much into it, and then bring it before a jury, because there's the old adage, 'When there's smoke, there's fire.' And that's something obviously as a defense attorney, we have to fight."

Brown did not respond to a later message seeking comment on the allegation of his client's past employment at Jones Beach and knowledge of Ocean Parkway.

Heuermann's attorneys, in a separate motion filed in January, asked for the case charging Heuermann with seven homicides to be broken apart.

Heuermann's attorneys suggested the state go to trial first on the three women whose bodies were found at Gilgo Beach — Barthelemy, Costello and Waterman — and then try the remaining counts related to the four other victims separately at later dates.

The motion argued that trying Heuermann for all seven homicides at once could have a "cumulative effect" on the jury, leading to an improper conviction.

In their court papers Tuesday, prosecutors cited numerous pieces of evidence linking the crimes, arguing against breaking up the cases.

"The victims are inextricably interwoven by geographic proximity, victimology, digital and physical evidence recovered, forensic analysis, and defendant’s own planning document," prosecutors said, referring to the alleged planning document found on a hard drive during a search of Heuermann's basement that prosecutors have called a killing manifesto.

Prosecutors said Heuermann's alleged choice of victims points to his methods, writing that all the victims share "the same gender, age range (all in their 20s), and physical characteristics (young, petite woman with most weighing significantly less than 145 pounds). Moreover, each of the victims were either known sex workers or described to be sex workers and shared the same socioeconomic standing, which made them particularly vulnerable. All seven women are connected on these bases."

These shared qualities "enabled the defendant to gain easy access to the victims and overpower them, as well as a window of time to evade detection, i.e., between the time they went missing and when their bodies were identified," prosecutors said in arguing the cases be tried together. "Since targeting young, female sex workers, who struggled financially, is unique to this pattern of crimes, it is indicative of an overarching modus operandi."

Prosecutors also alleged the disappearances and killings of the victims occurred when Heuermann had "exclusive and uninterrupted" use of his home because his wife and kids were out of town.

Prosecutors also said they plan to present evidence of Heuermann's "ties and familiarity" with the Manorville area, which is where remains of both Mack and Taylor were discovered, and to Southampton, where Costilla's remains were found.

Prosecutors also argued that their case, which includes "well over 50 possible witnesses that will overlap with regard to each of the seven victims" would be hurt if the charges are tried separately.

"The prosecution would be unfairly prejudiced by having to present this volume of witnesses at five separate, lengthy, and costly trials," prosecutors wrote. "Most importantly, granting the defendant’s motion would lead to the unjust result of precluding the jury from hearing the full narrative of events necessary to comprehend the instant serial homicide prosecution."

Attorneys for Heuermann in January also asked the judge to exclude testimony related to nuclear DNA results obtained from rootless hairs found at six crime scenes. The attorneys argued that the technique used by a California laboratory Astrea Forensics has not been generally accepted as reliable in the scientific community.

The Suffolk County District Attorney’s Office, in response to the defense motion, said the nuclear DNA evidence in the case against Heuermann should be admissible because the genome sequencing technique that provided the evidence is widely accepted in the scientific community.

A second outside lab also corroborated Astrea's DNA results through mitochondrial DNA analysis, the DA's office said.

Prosecutors have said Costilla was killed in 1993, followed by Mack in 2000, Taylor in 2003, Brainard-Barnes in 2007, Barthelemy in 2009 and Waterman and Costello in 2010.

By Nicole Fuller

nicole.fuller@newsday.com@NicoleFuller

Nicole Fuller is Newsday's senior criminal justice reporter. She began working at Newsday in 2012 and previously covered local government.