DNA Expert Analysis: Is Murdaugh Evidence Red Herring or Red Flag?

Summary

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Criminally Obsessed – Episode Summary

Episode Title: DNA Expert Analysis: Is Murdaugh Evidence Red Herring or Red Flag?
Host: Anne Emerson
Original Air Date: July 2, 2026

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Episode Overview

In this episode, seasoned investigative reporter Anne Emerson digs into the ongoing retrial of Alec Murdaugh with a focus on contentious DNA evidence—specifically, unknown male DNA found under Maggie Murdaugh's fingernails. Through a detailed interview with forensic DNA expert Tiffany Roy, the episode dissects whether new, state-of-the-art DNA testing could make a substantive difference in the case or if it's simply a legal tactic to sow doubt. The conversation covers the scientific capabilities and limitations of DNA analysis, the defense’s push for genealogy-driven testing using Othram labs, and the broader implications for justice, investigation, and strategy in headline-making criminal trials.

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Key Discussion Points and Insights

The DNA Under Maggie Murdaugh’s Fingernails: Game-Changer or Distraction?

• [00:00–00:54] The episode opens with Anne framing the central question: Could DNA found under Maggie Murdaugh’s fingernails exonerate Alec Murdaugh, or is its significance being exaggerated for effect?
• Defense points out the DNA “positively was not Alec Murdock’s.”
• “[...] we don’t think it’s a red herring. We think it’s very important.” (Defense, 00:10)
• However, expert testimony in the original trial noted it was only a minute amount of “touch DNA,” impossible to determine when or how it was deposited.

Understanding Touch DNA and Its Limitations

• [00:25–01:13] Forensic experts clarify the ambiguity inherent in analyzing trace DNA:
  • “If I shook somebody’s hand at some point in the day, could I have their DNA on my hand? It’s possible, yes.” (A, 00:53)
  • “I can never say how or when DNA was deposited on an item.” (D, 00:39)
• “DNA has limitations. It can tell us who is a potential contributor...But then in context, what does that DNA truly mean? [...] It can’t tell us how it got there.” (Tiffany Roy, D, 10:55)

The Push for Othram and Whole Genome Sequencing

• [01:24–05:17] Defense seeks to retest the DNA with Othram’s advanced genetic genealogy services, citing the lab’s role in high-profile cold case breakthroughs (e.g., Bryan Kohberger/Idaho 4).
• The state resists: “Prosecutors called more testing just a waste of time. They called it a boondoggle...” (A, 00:55)
• Roy explains: Othram uses “whole genome sequencing” rather than the standard “short tandem repeat testing.” Government labs typically don’t have access to this level of analysis; capabilities are “niche” and heavily data-dependent.
  • “Othram has capabilities to do different type of testing and it’s a lot more involved. It generates a lot of data, but it’s whole genome sequencing.” (D, 02:36)

Advances in DNA Technology – Perception vs Reality

• [05:18–06:53] Debate over whether the technology available now would have made a difference in 2021:
  • “In 2026, we are light years ahead...what we’re asking for didn’t really exist in 2021. It does exist today. And Othram is the leading lab that performs this analysis.” (Defense, B, 05:18)
  • Roy disagrees: “It’s my opinion that things have not changed substantially. This kind of testing has been around and it’s been available. It’s just the public awareness...that is a bit different.” (D, 05:47)

Touch DNA: Innocuous Transfer or Evidence of a Struggle?

• [07:13–11:26] Both sides debate the evidentiary significance of touch DNA under fingernails, especially absent physical signs of a struggle:
  • "DNA is a bit of a red herring [but]...worth looking into. Now, it may turn out to be, you know, innocuous. We don't know, but it's worth looking into." (Defense, 07:13)
  • Roy: DNA under fingernails could result from casual contact as easily as violent struggle: “We will never be able to rule out that it was someone from the Piggly Wiggly.” (D, 10:33)

Contextual Clues: The Missing Ring

• [11:26–13:59] Anne shares insights from conversations with the Murdaugh housekeeper, raising the possibility of a struggle based on the location of Maggie’s ring in her car.
  • “To me, the person that drove that Mercedes from the hangar back to the house after the murders possibly tried to take her rings.” (Housekeeper, C, 12:16)
• Roy clarifies how fingernail clippings are gathered and how the ring evidence could or could not be linked to the DNA findings.

Legal Strategy and the Role of "The Unknown DNA"

• [13:59–15:34] Roy discusses why the defense may have highlighted the DNA now, though it was known at trial:
  • “Sometimes this is legal strategy. Sometimes it’s better to just have the one-armed man than to identify whether it’s Buster’s DNA under her fingernails or...someone not a suspect.” (D, 14:23)
  • The mere presence of unknown DNA can plant doubt, even if deeper testing reveals it’s innocuous.

The Power and Limits of DNA in Court

• [17:09–18:42] Roy recounts cases where similar efforts led to an exoneration and stresses thoroughness in investigations:
  • “I have seen these longshot efforts work out...By being thorough and following up and answering all the questions...is the hallmark of a good investigation.” (D, 17:20)

On Genetic Genealogy and Its Costs

• [19:25–21:30] Costs are significant, sometimes thousands to tens of thousands of dollars, and ROI is uncertain, especially with limited samples.

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Notable Quotes & Memorable Moments

• On the Defense’s DNA Argument:
  • “It positively was not Alec Murdock’s. And so we don’t think it’s a red herring. We think it’s very important.” (Defense, B, 00:10)
• On DNA’s Limitations:
  • “I can never say how or when DNA was deposited on an item.” (Tiffany Roy, D, 00:39)
  • “It doesn’t tell you how it got there, it doesn’t tell you when it got there, it doesn’t tell you what the cellular source of the profile is.” (D, 17:44)
• On Whole Genome Sequencing:
  • “Othram has capabilities to do different type of testing...it’s whole genome sequencing...I think this is the right avenue to go down.” (D, 02:36)
• On Technology Advancements:
  • “It’s my opinion that things have not changed substantially...It’s just the public awareness of it that is a bit different.” (D, 05:47)
• On the Possibility of Longshot DNA Turning Cases:
  • “I’ve seen it happen, I’ve seen it work. And so I would never say...rare events happen all the time. Somebody wins that Powerball all the time. It’s not me, but I still play...” (D, 17:22)
• On Cost:
  • “No DNA testing is cheap...the genealogy investigation, that’s a lot of man hours.” (D, 19:38)

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Timestamps for Key Segments

• 00:00–01:13: Introduction and setup—what is at stake with the DNA evidence?
• 01:24–04:38: Interview with Tiffany Roy—the science and reasoning behind Othram testing.
• 05:18–06:53: How DNA technology and public perception have evolved since the murders.
• 07:13–11:26: Touch DNA’s evidentiary weight—practical and theoretical challenges.
• 11:26–13:59: The missing ring—housekeeper’s eyewitness clues and forensic process context.
• 13:59–15:34: Legal strategy—why raise the DNA issue now?
• 17:09–18:42: The real-life power and limits of DNA-led breakthroughs.
• 19:25–21:30: The economics and logistics of genealogy DNA testing.

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Conclusion

Anne Emerson’s conversation with Tiffany Roy provides both clarity and caution: while advances in DNA testing make it technically possible to chase down even the faintest traces of genetic evidence, interpretation is fraught and context-dependent. For all the courtroom drama over Maggie Murdaugh’s fingernails, the real story may be as much about legal strategy, investigative rigor, and the limits of the science as about technology itself. As Emerson and Roy underscore, DNA can be a red herring, a red flag, or—sometimes—a crucial clue, but never the whole story in itself.

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Did the DNA under Maggie Murdaugh’s fingernails point to a killer, or will further analysis just deepen the mystery? The story is still unfolding.

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Transcript

[A]

Hey, everyone, I'm Ann Emerson, and this is Criminally Obsessed. Could DNA under Maggie Murdoch's fingernails be the evidence the defense needs to get Alec Murdoch off?

[B]

DNA that we're talking about, you, Honor, came from Maggie Murdaugh's left fingernail. It positively was not Alec Murdock's. And so we don't think it's a red herring. We think it's very important.

[A]

During the original trial, an expert testified it was such a small amount of touch DNA, the scientists could. Couldn't tell us when it got there. Do you know when touch DNA gets something?

[C]

No.

[D]

I can never say how or when

[A]

DNA was deposited on an item. So if I shook somebody's hand at some point in the day, could I have their DNA on my hand? It's possible, yes. And you wouldn't know when that got there?

[B]

No.

[A]

Now the defense wants Othram, the same cutting edge forensic DNA lab that helped solve the Bryan Kohberger case, to take a look at that sample. It does genome sequencing, but the state says no. In its motion opposing the request, prosecutors called more testing just a waste of time. They called it a boondoggle, arguing there's no good reason to turn that DNA sample over to an independent lab.

[D]

It can be power. It has a lot of great power.

[A]

I called forensic DNA expert Tiffany Roy to better understand why Othram, why now? And what could that DNA tell us?

[D]

There's sometimes legal reasons why unknown DNA by itself can be helpful. And then it's dangerous sometimes to try to identify it because it can make it completely innocuous.

[A]

Does it feel like a long shot to you? Be sure to, like, subscribe and turn on your notifications here at Criminally Obsessed. I'm going to have a lot of updates to the Murdoch coverage. Now let's get into it. Tiffany, thank you so much for joining us. You know, we really could use your expertise as we dig into this Alec Murdoch retrial. There is so much information that looks like we need to. We need to start sifting through right now. Well, let's start with the DNA that was found underneath Maggie Murdoch's fingernails. Is this a good tactic by the defense to use Othram like this?

[D]

It really depends. So it's a different type of testing and what we would normally do at a crime lab. And what testing occurred in this case in the crime lab was called short tandem repeat testing. And this is standard testing at government crime labs across the country. Othram has capabilities to do different type of testing and it's a lot More involved. It generates a lot of data, but it's a whole genome sequencing. The Othram testing is just different. But not. I don't know any public crime labs that have the ability to do whole genome sequencing because it's so niche. It depends heavily on the data and whether or not the data is of sufficient quantity and quality to lend this information. So assuming it is, I think that this is a good direction for the defense to go in to try to identify the person whose DNA is under Ms. Murdoch's fingernails. That's, you know, that indicates close proximity. I don't know in the grand scheme of this crime whether or not there is any indication that there was a physical altercation. I mean, Ms. Murdock was shot from a distance. And so that doesn't indicate to me that what's under her fingernails suggests that there could have been contact between herself and her attacker. But I think it is important to tie up loose ends. We will want to know more information about that. And so this is, you know, developing that information and looking into it, I think is very important. It shows that we're being thorough. The investigation is thorough. Efforts are being made to. To not just tunnel vision, but to follow up on all possible leads in the event that Alex Murdoch is not guilty. I find that, you know, if the government has the goods, they should not be scared of this. And if they have the right guy, they should not be worried about this. Following up on these things just shows a good faith effort on their part. So I do believe that if the data and in these discussions with. With Othram suggests that it's suitable, I think this is the right avenue to go down.

[A]

One thing we do think we know is that investigators said that it came from an unknown male who.

[B]

So male DNA under her fingernails. Not from Paul, not from Alec Murdoch,

[A]

the foreign DNA to her. Yes. They were excluded as contributors when the murders happened five years ago. I think it's safe to say this. This kind of DNA technology, the work that's going on right now, it was just. It feels like a very different field. Am I right? Like, if you could help me understand why they think that things could have changed even in the last three years since he was convicted.

[B]

These murders happened in 2021. We're in 2026. 2021. There's no such thing as artificial intelligence in 2021. This genetic genealogy was just on the ground floor in 2026. We are light years ahead. Ahead. And so what we're asking for didn't really exist in 2021. It does exist today. And OTHRAM is the leading lab that performs this analysis.

[D]

And it's my opinion that things have not changed substantially. This kind of testing has been around and it's been available. It's just the public awareness of it that is a bit different. And there have been a lot more safeguards implemented. The tools that people are using are being improved all the time. And so databases like GEDmatch, which were kind of rudimentary back when this crime occurred, they have been, you know, commercially optimized now to make this more accessible to law enforcement and to people who are performing these kind of investigations. So I think the testing itself has really been something that has been available, and I think it's the application of the data to these more advanced searching tools to build out these trees and find more information. You know, these tools are being optimized to make them more accessible for public searching and for people to use these for this kind of investigation.

[A]

Well, Tiffany, I mean, like, when we talk about what a lab could do, I mean, this was also part of the argument for the defense. And just to be clear, as of right now, as we're talking right now, you know, there's been a motion filed by the state that they don't want to release this DNA evidence.

[B]

How sensitive touch DNA is. We're constantly shedding DNA and picking up DNA from others by shaking hands and door knobs and all the rest of it. So, you know, this. This is a bit of red hero. And Mr. Water said, well, there's no evidence of struggle, but there was a shell casing under Maggie Murdock's body from the gun that killed her. I mean, that shell casing and that gun had to be in very close proximity. Maggie Murdoch's cell phone was missing from the crime scene. Was DNA transferred at that point in time? And so we don't think it's a red herring. We think it's very important. Now, it may turn out to be, you know, innocuous. We don't know, but it's worth looking into.

[A]

Tell me, you know, what is it that if this DNA evidence was released, what is it that. That Othram would be able to do? Can. If we have a bit of partial DNA based on what we know, which is limited, and it sounds as limited of what the defense knows.

[C]

But.

[A]

But tell me what the. What OTHRAM can do.

[D]

Just theoretically, it's generating more information. These genealogy databases are not speaking the same language as the CODIS in the government lab. So we need somebody Like Othram, to develop a profile that's going to be in the same language as the genealogy databases. But also these kinds of investigations take time, right? You're going through public records, you're going through. You're building out genealogy trees and you're looking for common ancestry. And it takes time to, to do the actual genealogy investigation.

[A]

Well, and from what I've read in my layman's, you know, understanding of this, I saw that, you know, there was something like 20 data points that would be able to be looked at as opposed to an OAM analysis that would be like 500,000, a half a million data points. Is that correct?

[D]

Yes. So the. When we're doing the CODIS traditional testing, that's 20 different locations on the DNA. He's looking at the actual sequence of the whole genome. So it's, it's a lot more information.

[A]

Well, I think it's fascinating too. Like, as far as what that I've had a lot of people ask me, well, what kind of DNA? Like, is it like somebody that she had contact with at the Piggly Wiggly grocery store, like bagging her groceries? Or is it like somebody did it? Would it literally have to be like she was clawing at somebody that was coming towards her? You know, how much. What kind of DNA are we talking about?

[D]

And we really don't know. And even if I saw the results, I wouldn't be able to tell that. So realistically, the DNA doesn't tell us the source. Right? It doesn't say, this is a lot of skin cells. And so this must have been from a physical altercation. And it very well could have been someone she shook hands with or, you know, that she had just given a hug to. And so that's why I find it really interesting that they're so focused on what's under her fingernails, because I would like to know what other case information is suggesting that there might have been a physical altercation in this case. It doesn't appear to me from what was presented at the original trial that that was a case. So I don't know what their theory of the case is and, you know, what their thought process is, except that they would be interested to know that. And so we will never be able to rule out that it was someone from the Piggly Wiggly. That's one of the things that we need to keep in mind about DNA. DNA has limitations. It can tell us who is a potential contributor. If we can track that information down, especially, you know, using our databases and the tools, we have available to us. But then in context, what does that DNA truly mean? And it can't tell us. There's certain things it just can't tell us. And one of those things is how it got there. And one of those things is like whether it was a result of somebody clawing someone in a physical altercation or just from casual contact.

[A]

I've had several conversations with Blanca Trubiate Simpson. She is the Murdoch housekeeper. And I've done some episodes with her and had talks with her. And, you know, one thing she talks about is she actually. There was a ring that was found, one of Maggie's rings, just one of them. She, according to Blanca, had three rings on her ring finger. You talk about having to clean her car.

[C]

Alec had asked me to clean it up because he was going to. So I started cleaning out the car, moving on, you know, her stuff. And when I picked up the mat, the. Her wedding band was right there between the console and the driver's seat on the floor. So to me, the person that drove that Mercedes from the hangar back to the house after the murders possibly tried to take her rings.

[A]

Why weren't all the rings off of her finger? Why would one ring, one band of her ring be. Be fallen underneath?

[D]

And I think that, you know, relying on information like that, it can be helpful or it can be harmful. And I think, you know, I can only speak to what's general practice in forensics. I don't know exactly what happened in this case, but when someone goes into the medical examiner's office and they take the samples, they'll usually take a wooden stick and. Or they take the clippings from the fingernails and they'll clip them clean off and then they'll send the fingernails to the laboratory and then the laboratory will swab underneath the fingernails and try to see what exists underneath there. Or they will take a wooden sort of tool and they'll just do a quick swipe under all the fingernails and send that as well. So it's not going to be isolated to just one fingernail. We won't know if it came from the ring finger or not the ring finger. And, you know, it's really hard to know if, you know, Maggie just dropped her phone and it was on the floor and she was reaching for it and knocked off the exterior band or if that was a result of a struggle. So that might be why what they're relying on to say, you know, maybe there was a struggle beginning at this. Beginning in somewhere related to the car. And that's the basis for the defense requesting the additional testing on the fingernails, that could be the basis for that.

[A]

Well, and, you know, the defense had this information last trial. They. They knew that there was unknown male DNA that was found underneath her fingernails. Why do you think. Why do you think this was sort of not explored in the first trial?

[D]

Sometimes this is legal strategy. Sometimes it's better to just have the one armed man then to identify whether it's Buster's DNA under her fingernails or, you know, somebody that's related to the family and identify that as being somebody that's not a suspect. So a lot of this is legal strategy, and this time around, they're making decisions a bit differently. And I don't know, I wouldn't be able to know why. I mean, that's really for the lawyers. But, you know, there has to be. There's sometimes legal reasons why unknown DNA by itself can be helpful. And then it's dangerous sometimes to try to identify it because it can make it completely innocuous. So they're making just legal strategy decisions.

[A]

So it's not really that the DNA technology, in your opinion, has. Has, you know, sort of changed so dramatically that.

[D]

That.

[A]

That there's. There's a whole new field of possibilities here?

[D]

No, and I think it would have been. It still would have been available during his prior trial. So it's definitely advanced the field of genetic genealogy. But these technologies are not very different than what was, you know, available for in the first trial.

[A]

Well, because they were making a big deal about. Look what Othram did. They helped in the Brian Kohberger case with the Idaho four.

[B]

They had a DNA sample, they ran through codis, came up nothing. There was nothing. The State of Idaho Police Department, like, sled, had a contract with Othram. They sent the test. Othram. Othram does this genetic genealogy DNA analysis, and it comes back to a family member who had done a DNA test, ancestry test of the person who committed these murders, Brian Kohlberg. That's how they solved the Moscow murder cases.

[A]

But I'm hearing from you that maybe this is more just an opportunity to create doubt on Alec Murdoch, as it were.

[D]

It could be. I mean, it's an unanswered question, and I think the answers to the question could help Mr. Murdoch in his defense, or they might not. You know, and so I think

[B]

the

[D]

defense is operating as if this will be helpful, and then if it's not helpful, they'll. They'll just explain it away. As you know, it was just casual contact with the piggly Wiggly Bagger. So it doesn't hurt them, right, to get to answer this question. And I think that that's what they're weighing is like, if we can identify this and it's, it's some nefarious person, then that will be helpful to Alec.

[A]

Does it feel like a long shot to you right now?

[D]

I've seen, okay, and I'll say this, that I have a case, that

[B]

it

[D]

was a post conviction case and genealogy on a cigarette butt was able to lead to the actual killer. And so I have seen it happen, I've seen it work. And so I would never say it's, you know, rare events happen all the time. Somebody wins that Powerball all the time. It's not me, but I still play, you know, because I've seen these long shot efforts work out. And by being thorough and following up and answering all the questions, you know, following, chasing down every lead, I think is the hallmark of a good investigation. Whatever the answer, and then you deal with it. But I think I've seen it happen. So I would never say that this is a real log shot or this is something I've witnessed in my life and it's helped people, it's helped exonerate people. And DNA is one piece of the puzzle. And DNA alone, we've just talked about some things that DNA can't tell you. It doesn't tell you how it got there, it doesn't tell you when it got there, it doesn't tell you what the cellular source of the profile is. DNA in a vacuum isn't enough. It's circumstantial. It can be power. It has a lot of great power. But, you know, there should be more information that you know is being used in conjunction with whatever author was doing.

[A]

You know, if you had to explain this to a jury, what would you, what would you say about this DNA evidence?

[D]

I mean, if it's somebody that Mrs. Murdoch has casual relationship with or friend or a child or some other relative, you know, if there's an explanation of how that DNA could have gotten there that's innocent and scientifically plausible, then it's not very powerful. But if it's someone that she's never known and never met in a known felon that's been, you know, had exposure to other violent crimes in the past, that might be, that might be important. But it's, it's this information in conjunction with that other information. This information alone in a vacuum isn't going to, it's not going to do

[A]

it, is it Expensive to do this kind of work for Othram because I would, you know, Jim Griffin said we're paying for it. And the judge said, you absolutely are. I am not paying for this.

[D]

I don't think it's cheap. No DNA testing is cheap. So even if we send out for regular DNA testing at a private laboratory, it's thousands of dollars. And so, you know, this is a lot, especially the genealogy investigation. That's a lot of man hours. If they're worried about doing that in a six month time, imagine how much time hourly that a genealogist is going to be spending building these trees and searching through this information.

[A]

Yeah, that's interesting. And I don't know who's paying for it. That's one thing that we keep on asking. I'm going to keep on asking because you know, we've, we've asked who. He's completely broke. I mean Alec Murdoch is totally broke. So it's interesting to see where, where the money would be coming from. And we're talking about just a few alleles I guess of DN that they have to work with.

[D]

And that's, I mean, is this bang for your buck? Is this going to be worth it for the money that that's going to cost? Are you going to get any information from this? So that's highly dependent on the data. And I do think it's interesting like I always wonder if a lot of times like law firms and things will, will make a deal with their client for certain rights to the story and so they foot the bill on some of these things. It could be his own lawyer. That's them if they feel like it's worth it. But it's really hard for a lawyer to make this decision on their own to, to invest, you know, tens of thousands of dollars on this kind of investigation. If the data is too partial and the only person they've spoken to about it is Othram, which is a for profit laboratory. So is this a worthy investment of your time and your resources? And I, that's a big question mark for me right now.

[A]

Drop a comment below. I want to hear what you're thinking. Do you think the DNA sample is a red herring or a red flag? I want to hear your thoughts. Be sure to like subscribe and turn on your notifications here at Crimly Obsessed. Of course I am going to have a lot more on the Murdoch coverage.