Dateline NBC - Mark Sievers fights death sentence. Miami model accused of murder. Plus, John Wayne Gacy mini-series.

Episode Date: October 16, 2025

Dennis Murphy drops by to talk about the latest in the case of Mark Sievers, sentenced to death for murdering his doctor wife. He is trying to convince a judge to give him a new trial. A pre-trial hearing for the model and social media influencer who says she fatally stabbed her boyfriend in self-defense. Plus, you've heard of serial killer John Wayne Gacy — but what do you know about his victims? A new drama series from Peacock takes a closer look. Find out more about the cases covered each week here: www.datelinetruecrimeweekly.com Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.

Good morning. Good morning. You're listening to Dateline's morning meeting. They then put him under hypnosis. That is also on video. Our editorial team is catching up on breaking crime news. If she was innocent, what would their motive be? It's something to do with him being stabbed.

Maybe he stabbed himself. It is in the hands of the jury. Welcome to Dateline True Crime Weekly. I'm Blaine Alexander, filling in today for Andrea Canning. It's October 16th, and here's what's on our docket. In Miami, the case of the model who said she fatally stabbed her boyfriend in self-defense ramps up for trial. Prosecutors say it was murder.

So when police walk in, they find Clennie just cradling her boyfriend, there's blood all around the room. In Dateline Roundup, a medical examiner weighs in on the mysterious death of a Philadelphia teacher. And Donna Adelson, the Florida grandmother convicted of plotting the murder of her former son-in-law, speaks out at her sentencing. no knowledge that this horrible evil act was going to take place. Plus, a riveting new drama series about the victims of John Wayne Gacy. Andrea interviews the show's creator and cast. But before all that, we're heading to Florida, where a man sentenced to death for murdering his wife,

a doctor, tries to convince a judge he got a raw deal. Ten years ago in Sunny Benita Springs, Florida, Dr. Teresa Severs was making a name for herself in the field of holistic medicine, appearing on local TV shows and speaking at public events. Getting you healthy is my passion. Being healthy is your choice. When the devoted doctor didn't show up for work on June 28, 2015, her patients and her staff immediately knew something was wrong. Her husband, Mark, who was out of town, asked a friend to check on her at their home, and what that friend found was a bloody crime scene. 911, what is your emergency?

I'm at a friend's house, and I came here to check on his life, and he's dead on the floor. Teresa had been bludgeoned to death. Investigators quickly zeroed in on a suspect, Teresa's husband, accusing him of hiring his best friend and another man to commit the crime. In December of 2019, a jury convicted mark of murder, and he was sentenced to death. This week, more than a decade after Teresa's death, Mark is once again standing before a judge. He says he's innocent and that his case needs a second look. There is a lot to cover here, and there's nobody better to break it all down than my good friend Dennis Murphy,

who was covered this case extensively for Dateline. So, Dennis, thank you so much for being here today. Always a pleasure to be with you, Plain. So let's start by talking about Dr. Severs. She's this beloved doctor. Her husband was out of town at the time. How did he react to learning this tragic news? Well, it's not just a rule on Dateline 101.

It's also a law enforcement 101 that the spouse is always a suspect until he's not. Now, Mark Siever's alibi was that he was a three-hour plane ride away. He was up in Connecticut visiting with family. So he couldn't have been in the house. But he flew back down that day and was soon in a police interview room where things got really interesting. Tell me more about that because I understand. And I know that you have said that this was one of the more memorable interrogations on Dateline. People say you never know how anyone's going to react to a situation.

But in this interview room, he's crying, he's hitting himself, he's scratching. She had so much to offer the world. She was really, everyone says this about their wife. Their kids are special. My kids are phenomenal. Sure. It should have been home. Well?

She really is on track to change the world. Breathe. Breathe with me. Slow me down. My wife is so much better at this than I am. And then the police leave the room, but they can still hear Mark talking on the recording, apparently, to Teresa. Oh, my God, Teresa. What could I have done if I was with you, this wouldn't have happened.

If I came back, this wouldn't have happened. And then afterwards, once he kind of calms down, What does he tell police? He gets into a conversation with the detective there and says, you know, we had a good marriage. We had a few fights, but everything was okay. And then he says, but we did have an open marriage, which caught the detective's interest. Surely. And that raised a whole problem for them because they said, you know, are we suddenly now looking for a jealous husband or boyfriend who's the perpetrator here?

Before investigators could dive too deeply into Mark's relationships, though, they got this tip that came from far out of state all the way in Missouri. What was that about? Police down in Fort Myers, Florida, Lee County, get a call out of the blue from somebody they don't know in Missouri saying, well, you know, I have a friend named Wayne, and he wasn't around this week. And he has a very best friend named Mark Severs. And I'm watching on the Nancy Grace show that this Mark Severs has a wife who was just murdered. She starts to wonder what's going on. Does this friend Wayne have anything to do with the friend Mark who's got a murdered wife? So, of course, detectives said about finding Wayne, they bring him in for an interview, and what do they learn?

They learn that he's been a best friend of Mark Siever since the ninth grade. They've been the best men at each other's weddings. And Dennis, after some time goes by, Wayne ends up making this stunning confession to investigators, and he tells them that Mark had asked him for his help to kill Teresa. The plot had been hatched a few weeks before, according to the authorities. Mark Siever says to Wayne in a conversation, they're talking about, well, how's your How's your marriage to the doctor going? He says, well, it's not that great. I think she's going to leave me.

I'm worried about losing the kids. And by the way, there's more than $5 million insurance money in play here. I can give you a piece of that, maybe $100,000 if you'll do the killing. So Wayne, the best friend of so many years, says, yes, I'll help you out. But first I'm going to hire this kid I know, Jimmy Rogers, and I'll have him along the way to do this thing. Now, Mark Siever says he knows nothing about this, that Wayne is not a reliable person, and this is all coming out of his imagination. And that's really kind of the crux of the defense's case, right, that Wayne is lying about all of this and really tried to discredit Wayne as a witness.

Right. But in the end, obviously the jury agreed with the prosecution and Mark was found guilty. So now, Dennis, more than 10 years after Teresa's murder, Mark is back in front of a judge for an evidentiary hearing on his claims that the trial was unfair and his original attorney was ineffective. That's right, Blaine. There's this issue known in legal circles as death certified. If you're going to argue a case in court, you need to be death certified. And the lawyer at the time who argued the case, he was not death certified. So now they're saying maybe this isn't a pellet issue, that he was not qualified

and should not have been in that courtroom in the first place, though the lawyer was on the stand. And he said, everyone knew that I was not death certified. That was no secret. Okay. And he wanted you to represent him so much that he didn't mind that you were not death qualified. That's right. And the trial attorney went on to say that he did the best. he could to represent Mark. But there was one more thing that he was questioned about, right? Tell us

about that. Here is a very curious thing about this plane. When you look at the two of them, the two men, they look a lot alike. They're bald-headed men that have the same kind of Van Gogh beard, and they're creepily similar in manner. They brought the lawyer back in the sand, and he said, it has been alleged on the edges of this thing that Wayne had an infatuation with Mark Severs. Why did you believe that he was infatuated with Mr. Severs? So there were some text messages, you know, like little pet names and things like that. That just it kind of struck me as this may have been a relationship that, you know, maybe Mr. Wright may have wanted something more out of the relationship. They did not bring that up at trial.

And this is another one of the questions before the court is, why didn't you use that information if you had it? And he said, I thought it would inflame the jury. You know, if there are people on the jury who are homophobic, maybe they hold that against Mark. Maybe they judge Mark based on homophobia and not on the facts and the law. Severs has denied it. But it's one of the claims they're making of it would have been a more fair trial if they had erred these elements of the case. And we should say that Wayne denied having any sort of sexual relationship with Mark when police questioned him about. it. And Dennis, there's one more kind of hanging chat in all of this. It's this letter that has come

out to Mark's mother from Jimmy Rogers, the alleged hitman. What was that about? Well, this is after the trial. Jimmy Rogers comes forward and he says to Mrs. Severs, you know, your poor boy has been wrongfully accused here. He had nothing to do with it. But there seems to be an effort this week to hear more about what Jimmy Rogers knew and what he said later on. This is going to be fascinating to watch. We'll certainly be following this. And thank you so much for being here to break it all down for us. Blaine, take care. So good to see you.

Coming up, the case of the social media influencer accused of stabbing her boyfriend to death. She says she didn't mean to kill him. On April 3, 2022, a luxury apartment in Miami became the scene of an alleged murder. 27-year-old Christian Obamselli died after his girlfriend, Courtney Clennie, fatally stabbed him. Clennie, a 25-year-old Miami-based model and social media influencer with more than 2 million followers, said that it was all in self-defense, but detectives didn't believe her story. After a four-month investigation, she was charged with second-degree murder,

pleaded not guilty, and has been awaiting trial in jail ever since. This week, there was a hearing, as the case ramps up for trial. Kyle. Christian Cologne is a reporter at our NBC affiliate in Miami, WTVJ. Christian, thanks so much for joining us today to get us up to speed on all of this. Thank you so much for having me. There is a lot to cover here, and it's certainly been drawing a lot of interest from people. So just to start, kind of lay the groundwork for us. What can you tell us about the relationship between Courtney and her boyfriend, Christian?

Yeah, so this relationship is a classic example of what a toxic relationship, and we see that through the records. We have videos of the couple arguing, getting. physical inside a living room. There's another video of them, fighting inside some elevator in their building. They have multiple incidents of domestic violence where police were called to the scene. And police learned a lot from the building manager in this case. That person told police that since they moved in January, they had so many issues with the building, with the neighbors, just complaining, noise complaints. They heard arguments. And according to the records, the building was actually getting ready to kick the couple out and try to evict them because of so many

problems that the couple was having. Wow. So take us to April 3rd. According to the arrest warrant, the day started actually pretty peacefully, right? They were playing with their dogs in the apartment and just kind of going about a normal day? It seems that they were having a normal day, but from what we've learned about this relationship is that it could quickly become violent. So their beautiful day turned into violence when they just started fighting. According to Clennie's version, her boyfriend grabbed her by the neck, and he pushed her to the wall, then to the ground. Clennie is obviously from her version of the story.

She's freaking out. She picks up the phone. She calls her mom. Christian didn't like the fact that she was calling her mom. So supposedly he became very aggressive. And that's when she just runs to the kitchen. She grabs a knife. And then she claims that she threw the knife and it struck him in the chest.

That claim has been kind of challenged by the state attorneys because she claims that she was about 10 feet away when she threw the knife. So when police walk in, they find Clennie just cradling her boyfriend. There's blood all around the room. Christian, according to the medical examiner's report, had a wound that's about like eight centimeters deep. And so, Christian, the medical examiner's report is really challenging Clennie's version of events, right? Basically saying that if she threw it from that distance, then there's no way that the knife could have penetrated that deeply? Exactly. So that's Courtney Clennie's claim.

What is it, aside from that distance and the question of how it was able to penetrate so deeply, what was it that made investigators suspicious of that story? So the facts were there's a body. Clennie automatically that day, she confessed that she did it, right? So when it comes to the self-defense claim, what prosecutors look for is whether or not the victim or the person that claims to be the victim was caught up in some sort of fight. According to court documents, Plenty was found with no injuries to prove her claim that she was the one that was attacked. So what also led up to her getting charged is the videos of them fighting in the elevators.

There's audio recordings of her allegedly calling him a racial slur. So all this evidence gets put together. And prosecutors say, hey, this person has been toxic with the alleged victim in this case. It was clearly, for them, second-degree murder. Okay. And now we are in the march up to the trial. Now, this week, there was a hearing before the judge. Just tell us really quickly what that hearing was about.

So right now, there's a few pending motions in the Clennie trial. And one of the motions is that Christian, he was supposedly illegally recording Clennie. And those recordings are the ones that we have seen now as quote-unquote evidence of her toxic behavior. Defense attorneys don't want that evidence to be part of the trial. Another motion that's still pending is to reconsider bond. So defense attorneys say that new evidence has come in in the case, and they want Klanney to get some sort of bond. A lot of twists and turns in all of this. Thank you so much for getting us up to speed.

Yeah, thank you for having me. Up next, it's time for Dateline Roundup, the sentencing of Florida grandmother and convicted murderer Donna Adelson. Plus, you've heard of serial killer John Way Gasey, but what do you know about his victims? Andrea talks with the director and cast of Peacock's chilling new drama series, Devil and Disclays. Guys, John Wayne Gacy. Welcome back. Joining me for this week's roundup is Dateline producer Brad Davis. Brad, thanks so much for joining us today.

Glad to be here. So, Brad, we are starting this week with the case that you have been following now for years. We're talking about the 2014 murder of Florida state law professional. Dan Markell. This week, Donna Adelson, his 75-year-old former mother-in-law, appeared in court for sentencing after she became the fifth person convicted in his murder back in September. And, Brad, all of this was pretty dramatic. It really was. Don Adelson's husband, Harvey Adelson, read a statement in court. We've not heard from him before. He's always really been sort of in the background in the story in a way. He was at the airport when Donna got arrested. And we've heard

Donna and her son Charlie talking about him on some of the wiretap calls in this case, but we never really heard him speaking until now. So I was really curious what he would have to say, and it turns out, not surprisingly, he's really sticking by Donna. Donna did not participate in the heinous acts that she was convicted of doing. You're sending an innocent woman to prison. You have taken my wife and you have taken my life as well. And for what? This is not justice. It is vengeance and it is wrong. He gave an extremely forceful defense of his wife, saying she's innocent, and he went after the prosecutors saying they were spewing lies throughout the trial. He also blamed one-sided

media coverage for her conviction. We also heard from Donna, right? She had a chance to speak during the sentencing. What did she have to say? Yes, that's correct. She gave an emotional statement. She told the judge she was actually devastated when she found out her son-in-law was killed and insisted she had nothing to do with it. She claimed she became a second victim in all of this and would never do anything to harm him. I had no idea that other people planned to cut Danny's life short. And the people who did this are exactly where they deserve to be. But I had no knowledge that this horrible evil act was going to take place. If I had become aware of this plan before Danny was murdered, I would have stopped it.

Gosh, it's certainly stunning to hear her say that, and I'm sure that there were strong reactions from people who, certainly from the Markell family, who may have had their own thoughts about that. I'm curious, Brad, did any of this hold any sort of weight with the judge? No, it really didn't. Donna Edelson's conviction comes with a mandatory sentence of life in prison. It's first-degree murder. So after hearing all the statements, he still ended up handing down the same sentence. And Adelson has already been taken to jail, and she's on her way to a Florida prison. They just put out a mugshot of her from the Department of Corrections there.

She said that she has planned to appeal the ruling in the case and continues to work to prove her innocence. Next up, we are off to Philadelphia, where there was news this week in the case of Ellen Greenberg, the 27-year-old woman who was found dead in her apartment back in 2011 with more than 20 stab wounds, including tin in the back and neck. So Bradges, quickly bring us up to speed on this case. Right. So Ellen's manner of death has been a sort of. so debate for years now. The medical examiner initially ruled the death a homicide, then a few months later changed it to suicide. Ellen's parents filed a civil suit against the city for emotional distress, which settled on the eve of trial when local officials promised to take a second look at the case. And that brings us to the news this week. What happened? Once again, the Philadelphia

Medical Examiner's Office ruled Ellen Greenberg's death is best classified as a suicide. Did the medical examiner's office give any explanation for how they came up with this manner of death a suicide? They did. Chief medical examiner Dr. Lindsay Simon said in her report that a key factor in her decision was Greenberg's previous struggles with anxiety. Now, one of the sticking points, Brad, is that she was found to have been stabbed 23 times. How did the medical examiner explained that? Dr. Simon does acknowledge us in her report. She says, quote, the distribution of wounds is admittedly unusual, she says. However, she believes that many of the wounds are what she would call hesitation wounds. And she added that there was no one else's DNA.

on the knife or any evidence of anyone being in the apartment at the time of Ellen's death. So what comes next in this case? That remains unclear. Police may not reopen the investigation if suicide is the official cause of death. So the case is really at an impasse, it seems, at this point. And finally, a quick update out of Utah where Corey Richens, the mom of three, who wrote a children's book about grief before being arrested for her husband, Eric's murder, is still in jail awaiting trial. Prosecutors say Corey slipped a lethal dose of fentanyl into Eric's Moscow mule back in 2022, hoping to cash in on life insurance policies. She has pleaded not guilty to charges, including aggravated murder. So, Brad, what's the latest in this case? So Corey's defense team is

asking a judge to compel the handover of financial records from her husband's estate. Richon's defense has accused Eric's sister, who's the executor of his estate, of withholding documents that show she's been paying prosecution witnesses for their testimony. So has anyone responded to this allegation, Brad? Attorneys for the sister-in-law have admitted that the estate did pay two witnesses, but they were expert witnesses, they say, and these communications should be protected by privilege. We can expect to hear a lot more about this in the coming months as we await the start of her murder trial early next year. Brad, thanks so much for joining us on Roundup this week. We really appreciate it.

You bet. For our final story this week, we're going back in time. to December of 1978, and the gruesome discovery of 33 murdered young men and boys in a Chicago suburb. Four of them had been dumped in a river. The rest of them had been buried on the property of a local businessman by the name of John Wayne Gacy. Gacy, considered one of the nation's most prolific serial killers, has been the subject of countless films and documentaries over the years. But according to the creative team behind a new eight-part drama series, Devil in disguise, John Wayne Gacy, there's a side of the Gacy story that hasn't been told

before, the story of Gacy's victims, the victims' families, and the detectives who made an mission to identify them and bring them home. The detective said missing kids usually come home. What happens when they don't? Starting this week, the series, produced by NBC News Studios, will be available to watch on Peacock, the streaming channel owned by our parent company, NBCUniversal. Andrea Canning recently sat down with the show's creator, Patrick McManus, along with actors Michael Churness, who plays Gasey and Gabriel Luna, who plays the lead detective on the case, to talk about why it was so important to them to tell the victim's stories. Take a listen. So, Patrick, let me start with you. Why did you decide to do this show and shape it the way that you did?

The story that I keep telling everyone is just the true story, which is that I turned it down twice. Really? Yeah, I did not want to do it. And Universal Content, and Peacock, they came to me a third time, and they had said, well, you just take a look at the documentary. And I said, okay, and I watched the documentary that is on Peacock. It's brilliant. The documentary is really, really amazing.

But I didn't come away from watching the documentary wanting to do it, because at the end of the day, the documentary is very focused on John Wing-Gacy. And so I said to them, I said, look, if you will let me do it my way, and I didn't mean it in an obnoxious way, I just meant that I want to focus it on the police, I want to focus it on the lawyers, I want to focus on the victim's families. And to their credit, they said, yes. But I didn't know what I meant about focusing on the victims until we got into the writer's room. And we figured out this idea of doing the short stories, which is our attempt to be able to actually tell the victim's stories, but with absolutely no connection to John Wayne Gacy or their

murder. You know, not to take away the creep factor and the spook factor because it's all there, you know, the scary parts, but I think it makes it more digestible, focusing on that. We really hope that the word gets out to folks who maybe wouldn't be interested in a show about a serial killer, that this is an alternative sort of take on that story. Why did you decide to play Gacy? And you played him so well. Sometimes he's creepy. Sometimes he's like the guy next door. Sometimes he's funny. There's so many faces to him. There are, and that was, in my opinion, very true of the actual man. And so I knew that the role would be a real challenge in that regard.

There's really four Gacy's. John the contractor. John the politician. John the clown. And then there's the other guy. I had this great initial meeting with Patrick. He told me that there would be no murders on camera that we were focusing on the victims. And he said to me, like, I hope you're okay with you're not going to be in it.

all the time. And I was like, thank God. That's such a relief because to have to embody John Gacy all the time just felt like maybe something I didn't want to take on just for like personal mental health reasons. You've been told that you look like him? Is that? Here and there, people would say that and, you know, it's not the highest compliment. But yeah, you know, people would say like, well, you look like that killer clown. You should see him somewhere to write a show. or a film for you. And so it was always kind of in the back

of my mind. Yeah. Gabriel, you get to play the lead detective. Yes, yes. I was privileged to play Detective Raphael Tovar, the lead investigator on the case.

Police looking for John Gacy. Kids missing. Reported last scene with you. What did you take away as the most interesting part of your character? I think for me personally, I had played a lot of invulnerable characters. I mean, maybe physically invulnerable

in that they were robotic killing machines or superheroes with flaming skulls. And what I loved about this part was just the mundanity of his heroism. And you really captured the weight that the detectives carry with these cases. Well, yeah, but it's an interesting aspect of the show because so much of the show is also about the systemic failure of Chicago PD to actually have stopped him,

had multiple opportunities to stop him. But on the flip side of that coin, are a group of detectives who were in that pit every single day, who had their lives upended. And they were dedicated to ensuring that every last victim was found. And where we got really the inspiration for Tovar's entire journey, through the season was from a statement that he made where he said to this day he's still haunted by the idea that he didn't find everyone um you know there's still unidentified victims and one great hope of mine is that maybe through telling the story and just like shedding a different kind of light on it

that maybe we aid in putting a name to one or two or three of those boys that still uh are unknown of their identities. That would be amazing if something like that could come out of this. Absolutely. Yeah. Well, it has been a pleasure talking to all of you, and congratulations on this. Really just, I can't say enough good things. Thank you. Thank you so, so much to take the time. If you want to listen to more of Andrea's conversation with the team behind Devil in Disguise, we'll be dropping that in the Dateline feed on Monday. And all episodes of the drama itself are available to stream on Peacock right now. you'd like to dig even deeper, you can check out the documentary from NBC News Studios, also on Peacock. And that's it for this episode of Dateline True Crime Weekly. Coming up this Friday on

Dateline, I've got a brand new episode for you about a determined daughter who set out on a decades long quest to find her mother's killer. He just talked to me straight in my eyes. Like nothing was wrong. And he was comforting you. Yes. And he is the one who did it. Watch a perfect spring morning. this Friday at 9-8 Central on NBC. I can tell you it's an interview I will never forget. Thanks so much for listening. Dateline True Crime Weekly is produced by Carson Cummins and Katie Ferguson. Our associate producers are Caroline Casey and Logan Johnson. Our senior producer is Liz Brown-Kurloff. Production and fact-checking help by Sarah Kadeer. Veronica Mazaka is our digital producer. Rick Kwan is our sound designer. Original music by Jesse McGinty. Paul Ryan is executive producer and Liz Cole.

is senior executive producer of Dateline. Anybody have anything else I want to talk about? Okay. Come get the pumpkin bread if you're here while it's still hot.