The DNA That Unmasked a Killer

This episode contains distressing content. It's June 9th, 2024, and we're at Washington Dulles International Airport. It's Sunday, and a busy day on the concourse. Holidaymakers returning from trips abroad, mingling with business travellers flying out for Monday meetings. After collecting their luggage, thousands of passengers head towards the International Arrivals Building in the main terminal. The low hubbub of passenger chit-chat and the usual intermittent cry of an overtired toddler is accompanied by the occasional loudspeaker announcement, guiding travellers towards the customs inspection area. A passenger deposits his suitcase on a table for further inspection. He's in his early 40s, he wears glasses and has a neatly groomed beard. A member of US Customs and Border Protection takes a cursory look at the man's case and asks him to wait and then turns away before speaking into a two-way radio. After a moment, he turns back to the man and politely informs him that he's been selected for routine secondary screening. The officer leads the man to a small room set apart from the main concourse and asks him to wait. It's been a long flight from London. The passenger is tired and keen to get home. He picks up a small bottle of complimentary water that's been left on a table in the middle of the room. He drains the bottle, throws it in the trash, rubs his face and sits back in his chair. It's an inconvenient delay, but after the hustle and bustle of the airport, it's good to be in the quiet room alone. What he doesn't realise is that this is no random screening. The passenger has just been lured into a trap and the simple act of drinking from that water bottle will change his life forever. This is True Crime Reports by Al Jazeera where we explore some of the world's most shocking crimes. Today's episode, the DNA that unmasked a killer. The historic tree-lined streets of Washington DC's Chevy Chase District are home to one of the capital's most affluent communities. With its manicured lawns framing large luxury homes, this quiet neighbourhood in southern Montgomery County is one of the most sought after areas of the city. Chevy Chase, Maryland, has a national reputation for being sort of an elite, wealthy community where seldom does any crime occur. If anything happens in this neighborhood, maybe it's somebody, you know, going through a car for loose change, or maybe there's an auto theft periodically. But violent crime is unheard of in this particular portion of my county. This is John McCarthy. State's attorney for Montgomery County, Maryland. In 2001, he oversaw an investigation into one of the most violent crimes ever visited upon this quiet neighborhood. A brutal murder that would go cold and take more than two decades to solve. This was an extraordinary piece of work. It took them years to do this. One case. It's 10am on May 2nd, 2001. 48-year-old Leslie Prier hasn't arrived at the advertising and promotions company where she works. It's not like Leslie to be late, and when she doesn't answer her phone, her boss, Brett Reedy, becomes concerned. He decides to call Leslie's husband, Sandy, to find out where she might be. Her boss calls husband, you know, it gets to be about 11 in the morning and she hasn't shown up for work. They can't get a hold of her. You know, that's very weird. So they go, they go to her house. This is Dan Morse, a staff writer from the Washington Post. He specialises in crime reporting. I'm kind of naturally drawn to cold case investigations. They're just interesting in a whole number of ways. Leslie's husband, Sandy, and Bretts meet outside the family home. The scene that greets them when they open the front door is shocking. As soon as they walk in, they see blood in the foyer area of the house. Her husband, Sandy, is calling out her name. And meanwhile, the co-worker... When the dispatcher hears the description of blood in the foyer, she tells the two men to step outside the house. The Prayer residence is now a crime scene and there's no telling who might be inside. It was even unclear at that point if whoever did this was still in the house. So, you know, they listened to the 911 operator and they got out of the house. Montgomery County Police race to the scene. While Brett and Sandy wait, officers enter the property. Inside, there are obvious signs of a struggle. A table has been knocked over and there's blood smeared on the walls. This house is a classic center hall American colonial home where you walk into the house, almost immediately the stairs go up in the house and the officers who respond go upstairs and that's when it is discovered that Leslie Prayer is actually deceased. She's in an upstairs shower, catastrophic injuries, and the shower was on and scalding hot water was running over her body. They retreat, they go out of the house, they come down and they tell her husband that she is deceased, and the investigation begins. There's been no forced entry into the property. The only known people who have a key are the victim, Leslie, and her husband, Sandy. Sandy and Leslie had a single child, but that child was living independently. Their daughter, Lauren, was living outside of the family home. So the only two people in the house were the husband and the wife. Later, it's discovered that a back door was left slightly ajar. Police speak to the patrol officers who discovered Leslie's body. What they reveal about Sandy's behavior when they arrived on scene strikes detectives as unusual. And he's outside the house, police arrived, and they pull out their guns. And he says sort of nonchalant, almost... Not serious, like, oh, you guys are real serious about this. And so, you know, when that got back to the detectives that they started looking into it, they were like, well, that's kind of weird, you know. You'd think you'd be so rattled that your wife might have been killed or your wife might have been in there. You wouldn't be talking like that. While forensics sweep the house for DNA and fingerprints, detectives invite Sandy to the precinct for questioning. He claims that Leslie was alive and well when he left for work at 7.45 that morning. He tells police that he actually spoke to her a little later when she called his office around nine. But detectives can find no record of the call. And when they ask him about his movements the night before, he's vague on the detail. He kept saying, oh, I don't really remember what I was doing the night before. And then he said, oh, yeah, I remember. I took some computer equipment to the dump. And I, you know, I had to get rid of this computer equipment. And again, you know. People drive to the dump, whatever, but it's just kind of random and weird. And why would you have to do that at night? And why would you have to do that at that very time? The results of the autopsy serve only to fuel detective suspicions. The forensic pathology report states that Leslie's stomach contains undigested food eaten the night before police found her body. Detectives begin to speculate whether she was killed the previous evening. The evidence at the scene seems to support their theory. You know, in Sandy's telling, his wife was alive at 9 a.m. And then, you know, an hour and a half, maybe two hours later, she's dead. And the house had been cleaned. You know, whoever did this took great efforts to try to clean up the blood. So in the detectives' minds, they were like, well, how do you do all that? How do you... Kill someone and clean it up and move the body. What they were thinking was, well, you know, someone needed more time to clean the house and get out of there than... than the timeline that Sandy was presenting. There's also the violent nature of the murder. The forensic report paints a disturbing picture of Leslie's final moments. During the autopsy, when the doctor was looking at the wounds to Leslie's head, Yeah. there were a specific pattern. There was like a right angle to them, like these wounds to her skull. And they were able to match that to the baseboard in the foyer. That was the force and violence of this attack that they knew pretty early, that someone was, you know, ramming her head onto a wooden floor, but also kind of into a corner. You know, they were looking at the sharp. And they're like, oh, my goodness, that's the same pattern that is in these wounds to her skull. To John, the brutal nature of the murder suggests a crime of passion committed by someone who knew the victim. In most homicide investigations, particularly when you have something as violent as this, this was not, you know, a one blow or one shot or this was a lot of overkill. that sometimes there might be emotion and so the focus Fell on, just by the numbers, fell on the husband as potentially a suspect. And the police questioned him. And he was questioned very hard. Detectives drill down into Sandy and Leslie's relationship. They interview friends and family and learn that their marriage was under strain. They have money worries. And Leslie has begun drinking heavily. They lived on a very nice street. They both had jobs. Thank you. But there was a lot of credit card debt. There was some medical bill debt. And so, you know, there was stress in their life that wasn't quite obvious. Definitely they would argue. They would argue loudly. And they were much more financially stressed than you would know. Detectives question Sandy again. He admits that his marriage had become difficult, but tells them that he loved his wife and that he could never carry out such a horrific crime. Sandy cooperated, talked to the police, but denied any involvement in the homicide of his wife. After days of questioning, the police are getting nowhere. There's no direct evidence linking Sandy to the crime. Weeks later, after taking advice from his attorney, he decides to stop cooperating. And there's nothing the police can do. Theories are not why people get arrested for crimes. You have to have facts and evidence. And you don't arrest just for the sake of arresting somebody. You have to have a viable criminal case. Where you have some reasonable hope of convicting somebody on a crime. And clearly, I will tell you, this was disturbing to the community. Leaving this sort of open homicide in this neighborhood was something that was disturbing to Leslie's family. It was disturbing to her neighbors and her community. This kind of open homicide or high-profile case leaves its mark on everyone involved. Sandy remains the number one suspect, and not just with law enforcement. Leslie came from a large family. She had seven siblings. It was almost like a split in the family of Leslie's siblings, where the brothers thought, I didn't think Sandy did it. But some of the sisters actually thought he did it, and Leslie's mom thought he did it. So the effect this murder and this investigation had on this family was just... You know, it can't really be understated. But through it all, there's one person who refuses to accept that Sandy was capable of murdering his own wife, his daughter, Lauren. The one person who stuck by her father consistently and never believed it was her father was Lauren, their one daughter. Who maintained a relationship with her dad, never, never, ever believing that her father was responsible for what happened to her mother. But Sandy lived sort of under the cloud Two months after Leslie's violent murder, there are still no arrests and the police are running out of ideas. But it's now that new evidence comes to light. It will prove that Lauren was right to trust her instincts and it will expose a killer that no one could have suspected. It's July 2001 and in the affluent neighbourhood of Chevy Chase in Montgomery County, a community is living in fear. 48-year-old Leslie Prier has been brutally murdered and the killer is still at large. Police are running out of leads. Despite a lack of concrete evidence, Leslie's husband, Sandy, is their number one suspect. Nearly two months after Leslie's murder, they receive an update from forensics. This was sort of at the beginning of DNA becoming a big deal in... Homicide investigation. So they did, you know, they took a lot of samples from around the house, from Leslie's body, from under Leslie's fingernails, because, you know, if someone's being attacked and they try to fight back, they're scratching their clawing. And, you know, if they scratch and claw at someone's skin, there's a lot of DNA that they just scratched on hand. It took a while for the DNA to come back. This was in the days where, you know, it took a while. In 2001, U.S. law enforcement is beginning to benefit from the Combined DNA Index System, or CODIS. Set up by the FBI in 1998, CODIS enables detectives to compare and exchange DNA profiles to identify convicted criminals across state lines. They can also run a comparison with the DNA of all known suspects. The DNA profile is male. Detectives compare the sample provided by Leslie's husband, Sandy, and the results are conclusive. The DNA was not Sandy's. It was not Sandy under her fingernails. When police run the samples through CODIS, they also draw a blank. Whoever killed Leslie has no criminal record. Detectives change tack. They ask Leslie's daughter Lauren to draw up an exhaustive list of anyone who's been inside her parents' home. They begin to sort of identify, OK, who are the males? That come into this house on a regular basis, and they had somewhere between 18 and 24 males that were identified as potentially coming in and out of the house on a regular basis at that point in time. And they said, OK, let's get the DNA of all those individuals. Lauren provides police with a list of everyone she can think of that visited the house. She even includes the names of people she hasn't seen for months, and in some cases, years. She includes her partner, Scott, her uncle, Frank, who sometimes used to stay at the house, and even her first boyfriend, Eugene, who escorted her to her high school prom. Police contact any relevant names on the list, and the result is the same. Other males that were identified as regular occupiers of that house, their DNA was all analyzed. None of them matched up with the single source male DNA that was within the crime scene. By the front door, under her fingernails, in various locations, and by the back door, we didn't have the right person. It's another dead end, and almost inevitably, suspicion falls on Leslie's husband, Sandy, once more. There was even conversations about, or conjecture, did he hire a hitman, maybe it wasn't him, but it was somebody else. No evidence ever surfaced regarding that. It was merely... Considerations and theories you have in any homicide that you would really consider as kind of a red ball, where you really don't have any specific leads or any person you could point to logically who had a motive to take the life of this woman. By the end of 2001, the case has gone cold. It appears that Leslie's brutal murder will go unsolved and unpunished. In the months and years that follow, Sandy and Lauren struggle with the unanswered questions surrounding her death. From conversations with Lauren, journalist Dan Morse got to witness firsthand the devastating impact that such a traumatic experience can have. Through her, we were able to learn what an unsolved murder can do to someone and can do to a family. The fact that Sandy was a suspect. It really had an effect on his life and his family. For 16 years, Sandy Prier lives under a cloud of suspicion. He will never get to see justice served. In 2017, after a short illness, he dies suddenly from septic shock. Lauren says that her father died of a broken heart. Her mother's killer is still on the loose. It was widely thought in the community that he lived in. That Sandy killed his wife. To allow a man to live out his life, to allow this family to suffer, they spent some tough decades for her. It will be 21 years after her mother's murder before Lauren will finally get answers. It's 2022, and we're in a large filing room at the Montgomery County Police Station in Rockville. The square panel lights dotted around the ceiling illuminate a large packing table in the centre of the room and a couple of desks along the wall. There's a printer in the corner, multiple rows of filing shelves in the centre and the odd box on the floor waiting to be organised. On the shelves sit dozens of box files, each one representing an unsolved crime. Two women enter the room. One is carrying a file. After checking a reference number, she approaches one of the shelves, retrieves a box and sits at a desk. Her colleague picks up a phone. They call Lauren and say, by the way, we want to introduce ourselves. We are homicide detectives from Montgomery County. We're in a cold case unit, and we're going to go back and we're going to look at your mom's case. Detective Tara Augustine has only recently been assigned to Montgomery County's Cold Case Unit. She's been made aware of the Leslie Prier murder, and alongside Detective Alison Dupuis, she digs into the files. They do have some autonomy, these detectives, of what they want to look into. Thank And then also, Leslie's daughter, Lauren, would... You know, stay in fairly regular contact with that cold case unit saying, hey, is anything going on? Is anything going on? So, you know, I think that also piqued this detective's interest as well. The years following Leslie Prier's death have seen huge advances you. in DNA testing and the introduction of public DNA databases for researching family trees. Detectives decide to revisit the DNA evidence from the crime scene, but this time they want to widen the net. They've got this DNA sample from the crime in the blood. Fingernails, it's the same DNA. And so what they can do is they can compare that with DNA samples that have been uploaded into these, you know, commercial DNA things. You know, you take your DNA, you send it into any one of these companies. And you learn about your own history and where you came from. Accessing genealogical databases for the purposes of police work is not without controversy. A private individual's decision to share their DNA profile can expose genetic information from hundreds of relatives who've never consented to having their DNA data open to scrutiny. The base level concern is that I submit. My DNA to one of these companies, I thought the DNA was just being used for my own family research, for my own good. And now you're telling me that, you know, a bunch of cops are using it in a murder investigation. Using DNA testing for genealogical searches does have advocates in the wider world. In Argentina in 1976, hundreds of newborns were taken from their parents during a coup and given to military couples to raise as their own. Many were reunited decades later after authorities sent DNA testing kits to consulates across the globe. Back in the US, John McCarthy's state of Maryland was the first to enact legislation governing how law enforcement can use consumer DNA data to solve crime. There are certainly privacy interests and information that are contained within your genetic fingerprint. That you have a privacy interest in. And so before we're allowed to go out and mine that information, we need to go in and basically show the court that we've taken all other reasonable steps to kind of investigate the case. And in most instances where we're doing it, it's usually it's going to be largely rapes and murders because it's such a labor intensive. You're not going to do this for a minor offense. Having been granted a court order, detectives get to work. They're on the hunt for a similar DNA profile to the one taken from the crime scene. When they get a hit, they'll be able to build a family tree using other online information. They can then cross-reference members of that family tree with any persons of interest from the case files. It's a slow process, and at first, it appears fruitless. You know, they're going across the country and, you know, there's so many dead ends, you know, there's like, oh, these people, they're all dead, or they live in California, nothing, nothing, nothing. Over the course of many months, the detectives pursue a list of possible DNA profiles that all come to nothing. They refuse to give up. Then finally, in June 2024, the detectives think they might have hit on something. The profile that they found that had been submitted... For testing, we're two women in Romania, and they're like, whoa, what is that? I thought, you know, there's enough genetic similarities that if we can take these Romanians and build a family tree out from them, that's where you start, you know, we might get actually to the killer. It might be 5,000 miles away, but the DNA profile is similar enough for detectives to take notice. They begin to build the family tree and after some painstaking research, Detective Augustine lands on the name Gligor. She's certain she's seen the name before and it's not long before she remembers where. Within the case file, the name Gligor was mentioned, not because he had been tested for DNA, but because he had been mentioned in a note that he used to date the Gligar is the surname of Eugene, Lauren's childhood sweetheart. Remember him? He escorted her to the high school prom more than 20 years earlier. Eugene's name was on the list that Lauren had given to police, but detectives had seen no reason to question him. After all, Lauren had stopped dating Eugene years before her mother's murder, and the police already thought that they had the right guy. U.S. government statistics reveal that in around half of female murder investigations, the culprit turns out to be a current or former partner. To the police, who investigated the case back in 2001, Leslie's husband, Sandy, was the killer. Detective Augustine zeroes in on Eugene Gligor as the new number one suspect. She knew right away that they needed to learn as much as they could about this guy. And... She knew right away they needed to get his DNA. Detectives learn more about Gligar. He's still living in Montgomery County, just a few miles from the Preer residence. For the past two decades, he's held a number of jobs in sales and business development, and he's currently working for a local Maryland security firm. On the surface, he appears to be living an ordinary life. But when detectives dig deeper, they make some worrying discoveries. He's struggled with a drinking problem and been investigated for a number of burglaries, although never charged. He's been married twice. And in 2021, his second wife filed a petition for a protective order against him. Suddenly they're like, OK, you know, this is odd. And in her petition for the restraining order, it was, you know, this guy was punching walls. He was screaming He was screaming at me. I was really, really scared of him. After their divorce, Gligar's ex-wife became so scared that she moved house rather than risk a confrontation. The documents clearly indicate that Gligar has a propensity for violence, but it's not enough for officers to make an arrest. To do that, they'll need to test a sample of his DNA. On June 9th, 2024, they get the perfect opportunity. The police learn that Eugene Gligor is flying back from an international flight into Dulles Airport. They coordinate with security at Dulles Airport to basically set up a ruse. Detectives come up with an ingenious plan. It will test the legal boundaries of obtaining DNA evidence via deception. But if it works, the cops will get their killer. And that's how Eugene Gligor winds up in a back room at U.S. Customs and Border Protection at Washington Dulles Airport on June 9th, 2024. They tell him he's been preselected for enhanced screening. They bring him back into a back room for a few moments. They put some bottles of water on the table so that if he wants to have some water, he can drink from it. They're hoping he does, and he does. After they get done through and he finishes and going through the screening, he's released to go home. But because he drank from one of the bottles, they seized the bottle, they processed the bottle, they swabbed the top of that bottle, they forwarded that swab to be analyzed for DNA, and we now have, finally, a DNA test tells us. That that single source male that you've been looking for whose DNA is in four or five places around this murder scene and most particularly under Leslie's fingernails, it's all the same guy and it's Eugene Gligor. On June 18th, 2024, U.S. Marshals wearing body-worn cameras arrive outside Gligor's apartment building. When he steps out for a coffee, they make their move. Put your hands on your back, your hands on your back and here. Can you tell me what this is about? Yeah, you have a warrant. For what? I don't know. You got anything on your side? No. Officers transport Gligor to a D.C. police station. While he waits to be interviewed, detectives call Lauren to let her know that they've made an arrest. After he's in handcuffs, then Tara Augustine calls Lauren and tells her. And, you know, she says... You know, we got an update. Does his name Eugene Gligor mean anything to you? And she just, her mind went blank. She just couldn't believe it. Everything just flooded. Into her at once, she said she almost fell off the chair. She didn't really thought he could do it because that just wasn't Eugene in her mind. So just beyond stunning for her. 23 years after Leslie Preer's violent murder, police are confident that they finally have their man. I'm Detective McCrafton. This is Detective DuPoy. Hey. I'm from Montgomery County. I'm sure you're wondering what this is all about. I would really like to know. This has been really, really hard. Whatever's happening. Do you recall back in 2001, Leslie Preer? Yes, that she was murdered. Yeah. Okay, so that's the case that we are investigating. Gligor is happy to admit that he dated Leslie's daughter Lauren and says that they broke up a couple of years before Leslie's murder. When detectives reveal their incriminating evidence, he's less forthcoming. From the crime scene, the DNA that was taken, we actually have a sample of your DNA and it was compared to the crime scene DNA and it matched. So we know that you were there at the time when Leslie died. I never gave a sample of DNA. That's correct. We obtained a sample from a discarded water bottle that you drank out of. I don't know what to say. I have no recollection. I have no memory. I don't know what to say. I'm trying to give you an opportunity to be a little bit forthcoming before we... I mean, I feel very, I feel a little bit trapped here, like... Well, you're under arrest, so you should be trapped. Right, and so I think, you know, I mean, probably asking for a lawyer is my best course of action at this point. I mean, what do you think happened? I don't know. I can't verify. I don't know. I don't recall. I don't have any memory. I didn't do anything that you're talking about, so I don't know. And I don't feel like I can... I don't know how to answer it. I don't want to incriminate myself with questions. You guys are professionals. I'm not. I don't know. I really do think I need an attorney. I need to use the phone, and I need to call someone, and I need legal representation before I respond to anything else. Okay. That's fine. We're not going to ask you any more questions. There's no tears coming out of your face. I'm very dry right now. You're dry? I'm very dry. I'm partially dehydrated. You can probably see my eyes are bloodshot red because I'm just tired and drained. I don't know what's going on. You want me to drink water so I can pee? Like, what the **** is wrong with you? I don't want you to pee. I just don't want you to... What are you trying to say? I'm just trying to say that this seems a little put on. Are you kidding? No. Oh, my God. On the same day that Gligor is arrested, detectives charge him with first-degree murder and a court date is set for October 2025. Based on legal precedents, Gligor gave up his right to privacy when he threw away the plastic water bottle. But his lawyers want to get the DNA evidence tossed out by arguing that the trap set by police at the airport was illegal. Their argument is that Gligor's constitutional protection against unreasonable search and seizure has been violated. They say he was wrongfully detained when he re-entered the US because the reason given had nothing to do with border security. But they won't get the chance to make their case. Facing the possibility of life in prison, Gligar decides to take a plea deal. After proclaiming his innocence for an entire year, he finally admits to second-degree murder. It's a slightly lesser offence that recognises the murder was not premeditated, but it still carries a sentence of up to 30 years behind bars. I think that really speaks to the strength of the DNA in this case. I mean, they had his DNA. It's a direct match for the DNA under her fingernails. That's just... That is tough evidence to overcome. Detectives suspect that on the morning of May 2nd, 2001, Gligor decided to burgle the Preer property. He thought that there would be no one at home and he knew that Sandy and Leslie often left the back door unlocked. Tragically for Leslie, she hadn't yet left for work and she caught him in the act. In the heat of the moment, Gligor's violent instincts came to the surface. Now, more than two decades later, he'll finally pay for his crime. On August 28th, 2025, the judge sentences Eugene Gligor to 22 years behind bars. I'm very proud of the Montgomery County Police Department and its homicide unit in particular. This is a great victory for us. And, you know, hopefully these same kinds of tools can be used to bring peace to other families who have waited long and hard to get the same kind of answers the Pryor family now has. This was True Crime Reports by Al Jazeera. True Crime Reports is a production of Al Jazeera Podcasts. I'm your host, Hala Mahiaddin.