In addition to being gruesome, the case has charted new legal waters, as it has seen evidence from a newer form of DNA testing for the first time pass stringent court admissibility standards, setting an example in New York that could come into play in other jurisdictions.
Law360 sat down with Suffolk County District Attorney Raymond A. Tierney, who began prosecuting architect Rex Heuermann in 2023 on what now are charges that he murdered seven women, to discuss the case. Heuermann maintains his innocence, has pled not guilty and is in custody awaiting trial. His counsel did not immediately respond to a request for comment on the case on Friday.
This interview has been edited for length and clarity. To hear more of our conversation with Tierney, including material not included here, listen to the audio interview embedded in this story.
Can you tell us about the Gilgo Beach case?
The inception of the Gilgo case occurred in December of 2010, when four bodies were found along a deserted stretch of beach in western Long Island known as Gilgo. More bodies were found on the beach, and the discovery sort of caused a sensation. That investigation had been going on from 2010 'til I took office in 2022, so it had been a cold case for about 12 years. We formed a task force, looked at it with our partners and were able to charge seven murders.
The "Gilgo four" were Maureen Brainard-Barnes, Melissa Barthelemy, Megan Waterman and Amber Lynn Costello. Those were the original, and from there we were able to charge three other [homicides]. And all of them, save for Sandra Costilla — their bodies were … [or] portions of their bodies at least, were found on Gilgo Beach. Using a never-before-used DNA methodology in New York state, we were able to work on hairs that were found at the crime scenes and link them to either the defendant himself or three other women that he was associated with. Utilizing that evidence — as well as cell [phone] site data, billing records, internet search history, as well as the recovery of a planning document, in which the defendant evinced his motive in luring these women and killing them — we were able to put the case together.
I was wondering if you could tell us a little bit about how you came to use Astrea Forensics and about the admissibility of the DNA evidence — this is the first time that such evidence has passed standards [under the U.S. Supreme Court decision in Frye v. U.S.
, on which New York relies].So we said we were gonna start our investigation at the Gilgo four. During the recovery, the bodies were skeletonized, meaning there wasn't really a lot of forensic evidence that was available other than bone and hairs.
At the time, back in 2010, it was impossible to get a nuclear DNA profile from a hair shaft. [So we used] Astrea labs, which had developed what at the time was new methodology in which they were able to obtain a nuclear DNA profile from a hair shaft. At the time, they were really the only lab that was doing that. As we move forward, and now this evidence has been found admissible, this is the future, I would submit, of DNA analysis.
I think it's hard when you have some new technology that could be extremely useful, but there's only a few places you can employ to utilize it. That must be difficult for prosecutors.
Yeah. I mean, well the Frye standard is still, "Is it generally accepted in the relevant scientific community?" And really basically, if you look at this whole genome sequencing … where did that come from? That came from anthropology, that came from the discovery of genetic diseases, [from] identification of tiny genetic material that was found in the rooms of the Twin Towers. It was with regard to breast cancer and the BRCA gene — the way that young women know that they carry a high propensity to get these deadly cancers is because they test genetically. That's whole genome sequencing.
This technique was used in doing all of these great things in all of these other areas of science. What we did was we brought this into the forensic community, and the Frye standard allows us to do that. Now, the defense argued, 'Well, it's never been used in criminal court before, so you can't use it.' Well, if that was the standard, science would never move forward.
How does it feel to be the one to open the floodgates here?
I think it feels good in the sense that I think it'll help to provide closure to a lot of families and justice in a lot of cases where, for whatever reason, critical evidence that was left at a crime scene previously could not be examined in any meaningful way. Now we can do that. So it's exciting.
Dr. Green, who started Astrea Forensics, you know, he mapped the Neanderthal genome by going back and looking at ancient hair or an ancient bone. So he's the hair expert. And while a lot of these other labs will do whole genome sequencing, Astrea is still, when it comes to problematic DNA samples — especially hair and bone — they're the experts.
People I spoke with have concerns about potential privacy issues when it comes to revealing this much genetic information about someone who may be a suspect, and perhaps they are not guilty. Do you have any privacy concerns here?
With regard to privacy concerns, like if you murder a person and leave your DNA behind, that is no different than if you murder somebody and leave your wallet behind, you know? So I don't have any privacy concerns from that issue. So as we get more sophisticated and know that the DNA causes certain physical or mental conditions or diseases or whatever, yeah there's a privacy issue with that. But I think in the criminal forensic sense, we're not looking at that. And I think people who oppose a lot of the DNA on privacy grounds, they also oppose us looking at social media on privacy grounds.
And again, while privacy is important, in order for me to look at someone's social media, I need to get a warrant. And I need to show predication. … I need to show probable cause, right? Google will sell your personal information to the highest bidder, and there's no predication needed. It's just all for profit. It's all to exploit your tendencies and make money off you. Nobody has a problem with Google doing that, apparently, but they're gonna scrutinize me? Great. Scrutinize me all you want, because I'm getting a warrant for everything I do, and it's on, it's on paper, and it's signed by a judge.
Heuermann's defense attorney Mike Brown has implied publicly that issues — including that former Suffolk County police Chief James Burke was sent to prison for assault and obstruction of justice, as well as other past corruption issues with the Suffolk County District Attorney's Office — are going to somehow help him in terms of jury selection. Do you anticipate any challenges when it comes to picking a jury?
Just given the subject matter alone, not even thinking about the notoriety, it's gonna be challenging to pick a jury in this case, but we'll be able to do it. But with regard to allegations there were issues with the leadership in the Suffolk County Police Department — I mean, there were issues with the leadership in the county, yeah. I agree wholeheartedly with all of that, so you'll get no argument from me with regard to that, but that's not what this case is about.
Do you believe that you guys have presently identified all of the victims in this case?
It doesn't matter what I think; it matters what I can prove. The indictment is what we can prove. Each of the bodies on Gilgo that were found in Suffolk County, they're separate crime scenes. We're gonna work them as we've worked all of the Gilgo cases, and we're gonna follow the evidence wherever that evidence leads, whether it leads back to known defendants, whether it leads back to unknown defendants. But I think when law enforcement gets themselves in trouble is when they start talking about, "Oh, we see similarities, so this is what we think." Who cares what you think? What can you prove?
And we're saying we owe it to citizens of Suffolk County to start a cold case unit. So now we have all these bodies, some on Gilgo, some off Gilgo from between 1965 and to the present — we identified approximately 300 cases in which we said, you know, we should probably try to take a second look. And that's what we've been doing. Obviously, 300 of those vast majority are off Gilgo, but you know, at least nine of them are on.
Wow. Nine. So do you think that there could be other people involved? Why is Gilgo this dump site?
Well, I have an opinion, a fairly strong opinion about that. And maybe, hopefully someday I'll be able to share that opinion with you, because if I'm sharing that opinion, it means that I've charged individuals with the commission of those other crimes on Gilgo.
Is it normal to have this many cold cases? Data from Project Cold Case says there are nearly 346,000 cases of homicide and non-negligent manslaughter that have not been solved in the United States dating back to 1965. That's a huge number.
I think that tells me that unfortunately Suffolk County is not alone with this issue.
Do you have DNA evidence in connection with all those around 300 unsolved cases?
Some of these cases are so old, and also the evidence hasn't been properly maintained. Some suspected perpetrators have long since died. Some key witnesses are no longer with us. So, you know, a lot of those cases we're never going to be able to bring to court for a host of reasons.
But I think the first thing that we wanna do with each of those is, can we figure out what happened? The first cold case that we solved was the Eve Wilkowitz case. Working with the FBI, we did [investigative genetic genealogy], and we felt we found the perpetrator, but he had passed away, so the only way we could figure out definitively by our standards is if we exhumed that individual's body and took a direct DNA sample. We did, and then once we figured it out, we called up Eve's sister. Her reaction and the closure that she found made us realize that whether or not we can charge these cases, we have to as best we can figure out what happened.
--Editing by Amy French.
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