20/20 - The After Show: Home Alone

Episode Date: October 5, 2026

Othram founders David and Kristen Mittelman reveal how cutting-edge DNA technology helped unlock answers in the murder case of Allison Feldman…and how their work is transforming cold cases. To get ad-free episodes, early access to new true crime podcasts, and exclusive bonus episodes, subscribe to 20/20 True Crime+ on Apple Podcasts. ⁠Click here⁠ to start your free trial today. Terms apply. Learn more about your ad choices. Visit podcastchoices.com/adchoices

In Toronto, every arrival is a statement, and nothing says it better than this. Cadillac Optic was the number one selling luxury EV in Canada for 2025. Find your rhythm across a seamless 33-inch display and an immersive 19-speaker AKG surround audio system. This city demands agility, and Optic delivers with precision to make every drive extraordinary. Let's take the Cadillac. Find out more at Cadillac Canada.ca. Luxury sales claim based on S&P Global Mobility Canadian New Vehicle Total Registrations for calendar year 2025 for the Cadillac definition of luxury. Hi, everybody. Welcome to 2020 The After Show. I'm Deborah Roberts. And as always, it's so good to have you with us. And I got to tell you, you are in for a special treat today because we have brought in with us two groundbreaking scientists who have had a huge impact in the world of true crime. And if those of you who are true crime followers follow groundbreaking technology, you'll want to hear about this one. As always, we take a closer look at one of our most recent 2020 episodes. And this one was called Home Alone. And this one,

This one is the story where DNA technology became a game changer for investigators. It all centers around 31-year-old Allison Feldman, who was in the prime of her life. A new homeowner in Scottsdale, Arizona. It was a place that she loved. She was a successful medical supply sales rep. She worked with burned victims, and by all accounts, she was a caring and dedicated person, a bright light in the world. And then on February 17, 2015, Allison was murdered in her own home. Her boyfriend found her body after this brutal attack, and there were few clues about who killed her.

He was initially looked at as a suspect, but then was eventually excluded. So Allison's murder went unsolved for years until a DNA breakthrough led to an arrest. Now, as those of you out there who follow this kind of stuff, you know, DNA has factored often into cold cases that we cover on 2020. So today we thought we'd take a look at how it all works with the help of two people who are just doing incredible work in the field. David and Kristen Middlman. Their company, Authrum, uses cutting-edge technology to build DNA profiles that have been critical in solving some of the most infamous crimes all across this country. So David and Kristen, welcome. Thank you for having us.

Oh, my gosh. It's such an honor. Good to have you both here. And I've got to tell you, first of all, I mean, the work that you do, and you know that we have, look to your work a lot at 2020. You've taken part in some of our episodes. One of them called the code breakers where you helped solve a couple of cases. In fact, we were just talking, Chris, in six thousand cases. You both of this, more than six thousand cases you've been involved in. So we all know that, and we've heard, DNA technology makes a big difference. It's all about

genetics and matching and all of that. But before we get to talking about this case, let's talk about kind of what you do and how this works, how it matters. I mean, Kristen, in the simplest way that you can kind of help people understand why it's a game changer. Why? DNA is the most powerful biometric, in my opinion, when a crime scene happens, because you can't change it. People can change their appearance. So if they were caught on camera, they can look different. They can change their name. They can do something to conceal. They can even burn their hands and conceal fingerprints. I mean, People tend to get away with being able to hide biometrics. DNA is one of those biometrics you cannot conceal.

Yeah. And so I think it's one of the most powerful biometrics. And I think that up until now in investigations, people have used DNA at the end of an investigation to confirm that the suspect does match the DNA fund at the crime scene. Or in the CODA's database, that's the database run by the FBI in the United States, of known perpetrators to see if the person has committed multiple crimes, if they are a repeat

offender. But that was the limit of DNA up until Othrum started to exist a few years ago and up until we started to create new technologies. Well, before we get deeper into the DNA and this particular episode, I want to talk about you two, first of all, because what's so intriguing is you're not just scientists, but you're a couple. You met in the science lab, essentially, right, at Baylor College. And was it just the science? Was that the mutual attraction, Kristen? We were both one of six students that were scholarshiped. And so we got put together pretty early on in seminars. David was by far the smartest person in the room. I mean, two questions, and I knew he understood science better than anyone I had ever been exposed to. And I had been

exposed to a lot of Nobel Prize winners and scientists. So we started to talk about, my project. I was working on gene therapies and blind mice. And he actually built the treatments to cure the blind mice. At that point, I thought, if he can cure blind mice, he can fix anything. I break a lot of things. And so I'm taking with him. Yeah. I'm sticking with this guy. No, we've been inseparable ever since. We are probably the true epitome of opposites attract. We're nothing alike. Yeah. But I know what that's like. We're better. Yeah. We're better together. Well, David, how do you go from science and curing blind mice to solving crimes? Because you were really intrigued by cold cases and the idea that there were cases out there

that just were not being solved and science could play a part. Yeah, we spent years working in biomedicine. It's kind of a byproduct of training at a medical school. We were a Baylor College of Medicine, so we learn about cancer and disease. But as, as, you know, I continued in the university and doing just general research in biomedical science, I was really interested in high-impact problems that don't have a lot of solutions or a lot of people working on them. There's a lot of smart people working on cancer, on any disease you can imagine. And I became exposed to this problem in which there are tens of thousands of people that have been unidentified for years in this country.

over 300,000 violent crimes, sex assaults, homicides that have never been resolved. There's evidence available. And nothing's really been done since those cases have been unsolved to try to move them into a solved state. And so the idea that you could take DNA technology, which had grown and advanced quite substantially in other industries like medicine and bring it into this area, that felt really high impact. And it felt like no one was working on that. And just to really, just to really kind of drill in on that, you know, you can take a consumer DNA test at one of those companies and it'll show you on the map where you're from, where your ancestors are from, all this rich information. And the police get DNA from a crime scene and they just get basically a yes, no, is it in the database. And so the idea that they don't have access to basic tools that any consumer has access to, it just sounded crazy.

So we wanted to make sure that we could build technology that would provide at least that much resolution or more for investigators or to trying to investigate something that is also really important, not just where in the world are you from, but who murdered this person, who sexually assaulted this person. All right, well, hold that thought because we need to take a quick break. And when we come back, more from David and Kristen about how this technology is changing lives. Don't go anywhere. I started or not in 2013. And we make bike apparel. The best part of Shopify for me is our ability to run the business as essentially non-technical people. We're able to admin everything on the back end, front end, and sell things online easily.

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What are you waiting for? Tis the season to start selling. Start for free at Shopify.com. Welcome back to 2020 The After Show. I am here with David and Kristen Middellman, who work in for rentals. genetic genealogy, getting a great masterclass in what this is all about. You mentioned CODIS earlier, and we've all heard about that, that database, but the idea that you're able to kind of go beyond that, right? And give us a sense, because people know a little bit about this, but they don't really know the details of the science behind it. So over the years, it's been

kind of hit or miss, right? So when police can gather, you know, some kind of a sample from a crime scene, they can run it through that KOTIS lab, but if the person hasn't been arrested or anything like that, it's not going to, we're not going to get a hit. So how do you, how did you sort of overcome that idea? Yeah, so, so, so this Kodas system that the FBI runs, it's a registry. It's kind of like, imagine the yellow pages. And you can find things in the yellow pages if they're already there. So Kodas is the same way. If you've got a known offender and that known offender's DNA gets into the database, not all known offenders get to COD's. Sometimes the DNA doesn't make it.

It's just like you have sexual predators that don't always make it on the sex offender list, and they should. So there are not, there's not a perfect process. But generally, if you're a known offender, you'll have your DNA profile put into this database. And like the yellow pages, they can basically look up your identity if they find your profile at a crime scene. The problem is, if you have not been caught, if you didn't make it into the database, if the crime predated the broad use of CODIS, right?

If you're a victim, what if they find remains somewhere because you're the victim of a crime? Why would a victim be in CODIS? So if any of these other situations happen, then there's not going to be a match. And so that's why we kind of call the CODIS search, like a chance match opportunity if you might be in the system. What's different about what we do is that we're building DNA profiles

that instead of having, you know, a handful of DNA markers, CODIS is like 20 data points. we take half a million data points in your DNA. And with a half a million data points, instead of looking for an exact match or for a parent, child, or something relationship, we can look for the most distant relationships because in the end, we're all kind of one big genetic family.

I sometimes describe it as like a human tapestry. That's what our DNA is. We're like all part of the same tapestry. And somehow we're all related to everyone. We're one big family. And so if you have enough data points, you can draw these long-range connections between people. And you can say, based on all this information,

here are a dozen people that are not closely related to you, but they're loosely related to you. And if you know who they are, you can then begin to build family trees for those people, figure out who their relatives are. And as you build out these family trees, if you're related to everyone that you're building the tree for, you'll be somewhere in that tree.

And so this is a different approach. Instead of looking someone up like you would in the phone book, what you're really doing is you're doing something that's more akin to like GPS. The DNA is a GPS signal, and all these families and records and trees are essentially the map, and the DNA puts you somewhere on the map, and you can use essentially process of elimination to figure out where on this family tree you might be. And that allows you then to find people, their identities, even if they're not actually

directly deposited in a system like CODIS. Well, that's so fascinating when you talk about the family tree, because that's a way of kind of understanding it. And I think, Kristen, you have said, and you said in the episode Friday night, which we're going to talk about in a second, that it's like, well, you said it's like a camera. And you said DNA is like, you know, it's a metric, right? It's like a clear metric. It's either you or it's not you. Correct.

Yeah. Yeah. Science, of course, is 90 plus percent, right, positive. But do you ever worry that science could be wrong and maybe you got it wrong? Or do you feel pretty confident in everything you do? I don't worry. The problem with this science is false. negatives, not false positives. Once you have those matches and you've built that family tree

and you've given law enforcement that lead, that's because you were able to get a good profile. But the evidence in some cases is treated in a way that we can't get enough of those markers, enough of that information to do so, and that's a false negative. So that doesn't mean that that that case can never be solved. It just means we're not getting enough information from that evidence right now it's not tractable but once we have that lead because we're looking at hundreds and hundreds of thousands of markers and because DNA is such a powerful biometric where you know we are all different it is not possible to have a false positive and the technology is confirmed with the codis test after the fact so beyond just us giving that lead and investigators confirming it using SNCC

technology, they then collect DNA and do an STR test with those 20 markers and they're a match. And that's the technology that's gone to court for 30 plus years. And we've now been in so many trials across the country. We've been in trial more than any other person using this technology. We have never seen the evidence be dismissed or not used. So that's interesting about the false positives versus the false negatives. Interesting. Yeah, most of the time you just miss the answer. Yeah. And so you've consumed the evidence. And this is not evidence you can get more of. So you're saying you might miss that person who's guilty more than you would actually get somebody who is not guilty.

You're getting half a million DNA markers, right? So the odds that you would compute the DNA markers wrong. Like if I had a DNA profile for me, the odds that I could mess up the profile and it suddenly matches you is very low. I'd have to change hundreds of thousands of letters to just magically match yours. The more likely problem would be that I got the letters wrong. and now I'm not going to see a relationship that should be there, right? Because if we're related, we share markers. If the markers are wrong, we don't share them anymore.

Now you can't see us. So that's what Kristen means by false negative. Well, it's really fascinating. And I do want to talk about Friday night's episode. While you weren't a part of that case, you definitely weighed in for us on this case. And as I mentioned earlier, our episode in that episode, DNA became a crucial part of zeroing in on Alison Feldman's killer. So we're going to take a quick break.

So don't you two go anywhere? And don't you go anywhere? Because when we come back, we're going to talk about a tiny stain on Allison's floor and how that wound up helping solve her murder and other details that you haven't heard. So stay with us. Don't go anywhere. In Toronto, every arrival is a statement. And nothing says it better than this. Cadillac Optic was the number one selling luxury EV in Canada for 2025.

Find your rhythm across a seamless 33-inch display and a number of number. immersive 19 speaker AKG surround audio system. This city demands agility and optic delivers with precision to make every drive extraordinary. Let's take the Cadillac. Find out more at Cadillac canada.ca. Luxury sales claim based on S&P Global Mobility Canadian new vehicle total registrations for calendar year 2025 for the Cadillac definition of luxury. Welcome back to 2020 The After Show. I am here with two incredible scientists, a merit couple, David and Kristen Middellman,

founders of Authrum, Inc. experts in forensic DNA testing. And we're taking a look at the Allison Feldman case, which is the story that we just covered on 2020. It was called Home Alone. I should mention that you did not work on this case per se, but you observed it for us, and you helped us kind of understand a little bit about the case. And it was so interesting because this was one that was very hard for police, and you two have encountered this a lot, where police are stumped, right, even though they have maybe gotten some evidence from the scene, And in this case, somebody had attempted to clean up the floor, right? So she's found murdered.

There are very few clues there. And someone appeared to have tried to clean up the floor. And I'm sure you run into that too. But is there still DNA present oftentimes when that has happened? Absolutely. It's very hard to commit a crime and not leave some DNA at the crime scene. And even if you've tried to conceal it or clean it up, we have worked hundreds of cases. where there's chemical cleanup that has occurred

and we're still able to build one of these DNA profiles. That's shocking, really shocking, because that tells you how fine the science is, right? And in this case, that was something, there was a tiny, tiny speck of something that really made a difference, David, right? Yeah, a stain that had a presence of DNA and that DNA was able to be lifted from the material,

purified, and then tested. And we do a lot of stories about old cases, cold cases and how the new DNA played a big part. Let's talk about in this case in Allison's case. So police kept looking, kept looking. They were searching and not doing very well with their search in terms of making an arrest. They apparently fanned out to like more than a hundred people who were ever connected to Allison Feldman's life, right? Trying to get a sense of DNA and how that would play out here. And there was a new tool familial DNA. What is familial? DNA mean? So when CODIS was built and it was nationalized in 1994, it was built under the idea

that you could collect 20, about 20 markers is what they collect now for a person, use that to index people that are known offenders. And then if you find 20 markers at a crime scene, you can do an exact match to see if those 20 markers are already in the database tied to a known person. familial search extends that a little bit more and says, what if we find some of the markers match, 15 of the 20 markers match? Could that be evidence that there's someone that's a close relative in the database? So instead of just being able to find you in the database, perhaps you could also find someone that's a parent or child relationship or a sibling. It doesn't work much more than that. You could imagine, let's say, you and I were a brother and sister, and we have 20 markers.

you may have gotten, you know, a good amount of your markers from mom. I got mine from dad. We'd only share 10 markers. If we were even half siblings or cousins, there wouldn't be enough markers to even measure that. But familial search can measure a close relationship, parent, child, or sibling. And put you kind of close in the proximity, which is what happened in this case. So the suspect that police began to look at, as people saw in our piece on Friday night, I Am Mitchum, had a brother who was in prison.

and they were able to sort of connect those two because he had multiple brothers, but they were able to kind of zero in on who was in the area near Allison Feldman. And that was what kind of led them to her. What did you make of that, Kristen? Yeah, that's exactly what happened. So when they uploaded the DNA from the crime scene to Kodas, it wasn't a direct match, but it was a match to his brother. and they looked at, because he had multiple brothers,

they looked to see which one would make the most sense. They start to contextualize that information to see who might have been in the area. And they did think, yes, Ian was the brother that made the most sense. And so they decided to zone into that and make sure that they could confirm the relationship between him and the DNA profile

that was found at the crime scene. So that was actually the way they were able to kind of pull this all together. And he was a total stranger. And ordinarily for police, they're stumped sometimes when this happens. He had been stopped for a DUI at some point. And then there was question about his DNA. And then, of course, that goes into the courts. And so we talk about that. I'm curious for you two, having worked in this field for so long and you feel so certain about it. But then there are legal barriers from time to time sometimes about how DNA was collected. or whether or not doubt can be cast on it. I think that's why there need to be guardrails and how this work is being done. What happened in this case is instead of going to collect new DNA from ion and confirm that his DNA was 100% match in the CODIS system to the DNA left at the crime scene, they first wanted to confirm it using the vial of DNA that already existed from the DUI arrest. And that DUI arrest didn't consent that vial of blood to be tested for anything other than the blood alcohol level in that vial of blood.

And so that led to the defense saying, well, that was an improper use of that vial. And even the Supreme Court in Arizona agreed that that was improper use, that that was not consented for that use. The reason they allowed the DNA evidence to remain is because during the CODIS upload, you had a direct match to his brother. And so if that vile blood didn't exist, then they would have gone and gotten a warrant to test his DNA. And so it would have been inevitable that that would have been the next step. Which is what the court ruled. Which is why they ruled what they did.

Yes. But I do think that the more guardrails that exist, the more that law enforcement is trained to immediately go and get that warrant to collect the DNA from the person rather than to look for that first place that you could test the DNA to confirm your hypothesis because they could have gone the other direction. And so I think guardrails are very, very important, even sitting here as scientists. And in this case, Mitcham actually was convicted. He, earlier this year, He was tried and convicted of Allison's murder. And the DNA did play a huge part here.

I'm just wondering what that's like for you too because it's the science and you do this and you help solve the cases, but ultimately families get some resolution, right? And that's got to be gratifying. I mean, even just watching a case like this that you weren't a part of, others you have been, that must be gratifying for you too.

You can think of these crimes as having a blast radius. There's the person that is, you know, the center of the victim, in this case, Allison, who is sexually assaulted and murdered. But the longer it takes to solve the case, the greater the blast radius of damage. Her family suffers, her friends suffer, the community suffer. So it's really paramount to address these cases as they happen as quickly as possible because you can't reverse the crime, but you can at least contain or try to limit the amount of damage to everyone else. And when it takes years or decades, sometimes family members don't live long enough to get the answers. So it just cannot express, even for the older cases, how urgent it is.

We've never worked a case, even cases that are very old, where there isn't someone that still remembers a person that's been waiting and has been tortured because they don't have an answer. So there's an urgency no matter what age the case is to identify it, to make sure that the person responsible hasn't done other things or will not continue to do things. and that the family and friends can get an answer as to what had happened to their loved one. Well, you're changing a lot of lives, Kristen and David. Thank you so much for being a part of not only this program, but many of our 2020 programs. Good to have you here and to explain a little bit about what you do. And thank you for being with us and spending some time with us today. And, of course, you can always catch 2020 on Friday nights on ABC and stream episodes like this one anytime on Disney Plus and Hulu.

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