Law&Crime Sidebar - Missing Scientist’s Autopsy Reveals Chilling Twist

Episode Date: August 11, 2026

The newly released autopsy report for Melissa Casias, a Los Alamos National Laboratory employee who vanished from Taos County, New Mexico, reveals she died from a gunshot wound to the head, but officials have officially ruled her manner of death as undetermined. As her grieving family pushes for answers and raises questions after hiring private investigators who uncovered additional remains and evidence left behind at the scene, serious doubts emerge about the handling of the case. Law&Crime's Jesse Weber breaks down the critical medical findings with former FBI Special Agent and crisis management expert Daniel Brunner.HOST:Jesse Weber: https://twitter.com/jessecordweberLAW&CRIME SIDEBAR PRODUCTION:YouTube Management - Bobby SzokeVideo Editing - Michael Deininger, Christina O'Shea, & Jay CruzScript Writing & Producing - Savannah Williamson, Heather Berzak & Juliana BattagliaGuest Booking - Alyssa Fisher & Diane KayeSocial Media Management - Vanessa BeinSTAY UP-TO-DATE WITH THE LAW&CRIME NETWORK:Watch Law&Crime Network on YouTubeTV: https://bit.ly/3td2e3yWhere To Watch Law&Crime Network: https://bit.ly/3akxLK5Sign Up For Law&Crime's Daily Newsletter: https://bit.ly/LawandCrimeNewsletterRead Fascinating Articles From Law&Crime Network: https://bit.ly/3td2IqoLAW&CRIME NETWORK SOCIAL MEDIA:Instagram: https://www.instagram.com/lawandcrimeTwitter: https://twitter.com/LawCrimeNetworkFacebook: https://www.facebook.com/lawandcrimeTwitch: https://www.twitch.tv/lawandcrimenetworkTikTok: https://www.tiktok.com/@lawandcrimeSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

We have been asking ourselves for nearly a year what happened to Melissa Casillas, a gunshot wound, a bullet passed through her skull, a firearm even found nearby, but here is the kicker. The medical examiner won't say if this was a murder, an accident, or something else. The official autopsy report has just been released, and we are going to break it all down for you right now. Welcome to Sidebar, presented by Law and Crime. I'm Jesse Weber. We have been waiting.

We have been watching. And finally, we have answers. Or do we? You'll remember, we've previously discussed the mysterious circumstances surrounding the death of Melissa Cassius, a wife, a mother, 54-year-old administrative assistant

at one of the world's most sensitive national security labs, Los Alamos National Laboratory. She vanished in June of 2025, and almost a year later, hiker found her remains in a remote, desolate area of the Carson National Forest. And now, finally, the autopsy report has been released.

A gunshot wound to the head, a bullet that traveled right through her skull, and a firearm found near her body. But this is where it gets complicated. The medical examiner has ruled her manner of death undetermined. So not homicide, not by her own means, not an accident. I mean, at least for sure, it's undetermined. We don't know. That's about to open up a whole new chapter in this case because Melissa's family, they're not accepting this. They believe that she was killed. And they have evidence, evidence that they found that law enforcement apparently didn't find, which we're going to get into a little bit.

But what is the autopsy actually tell us? And that's what we're going to get into. But first, just to quickly give you the circumstances surrounding Melissa Cassius's death. So strange. Talk about it right from the start. According to NBC News, your husband, Mark Casillas, who also worked at the lab, apparently told investigators, that she dropped him off at the lab that morning and said that she was going to another location within the lab to complete a work task. The problem is she apparently never made it there. Instead, she reportedly returned home after realizing she had forgotten her badge. Her daughter saw her that morning at around 7.45 a.m. Later that day, family members went to the house, found her purse, identification, cell phone's still there. This is according to New Mexico State Police. And here's the thing that really stood out. Two of her phones had reportedly

been factory reset, meaning they were wiped. That same afternoon, June 26, 2025, a family acquaintance spotted Melissa walking eastbound on State Road 518. This was captured on security video from a local business. And that, as far as we know, was the last confirmed citing of her. New Mexico State Police P.I.O. Sergeant Ricardo Brissetta told Dateline, she has observed walking eastbound on NM-518 and wearing the clothing she was last reported wearing in the Taos Plaza. It is difficult to tell if she appears distressed. And then nothing for nearly a year. No answers. The family searched, volunteers searched, law enforcement searched. Melissa, nowhere to be found. You fast forward. You go to May 28th of this year. A hiker discovered human remains

in the McGaffey Ridge area of the Carson National Forest. And according to New Mexico State Police, a handgun was found alongside those remains, which were skeletonized. the office of the medical investigator positively identified the remains as that of Melissa Cassius via dental records. Now, you may remember in our last episode, we talked about some really troubling new developments. According to LA Magazine, the Casillas family hired their own search team who headed back to that remote area where her remains were found. And according to their attorney, they discovered items that had never been mentioned before. And this really stood out. Melissa's sister reportedly recognized her handwriting in these shepherds.

shredded papers that were found. So the question becomes, how was this evidence not uncovered sooner? What does it mean for the investigation? But now we have the autopsy report. And I want to break it down. I got a special guest, Daniel Bruner, former FBI special agent, crisis management expert, FBI SWAT tackle operations team leader with extensive experience in these kinds of crisis situations. I'm so happy to have you. I have so many different questions about this. Thank you for taking the time. No, it's my pleasure, Jesse, anytime. So let's get right into it. This autopsy report is finally out. We've been waiting for it. There's a lot to unpack. I want to start by reading directly from the report.

This is from the Office of the Medical Investigator. And it says, quote, on May 28, 2026, field deputy medical investigator Christopher Martinez was contacted by New Mexico State Police about skeletal remains located on McGaffee Ridge in Touse County that had been discovered by a hiker. The hiker stopped to enjoy the view and notice the remains on a rocky outcrop. The location of the remains was in a position that provided a view of the surrounding mountains. So, Daniel, let's start there. You got this hiker, just happened to stop, sees it. There's been a lot of questions about why these remains were discovered so long after, you know, she went missing. And in this particular location, what it stands out to you about it?

Listen, there's a lot that just doesn't make sense about this case. And, you know, the positioning of the body, the location. of the body. From what I understand, this is an extremely, extremely remote area of the park, where it is, it is not like right off the road. So supposedly that one of her last sightings of this woman was seen walking on the New Mexico roads there, you know, and she had a backpack. And then all of a sudden she's now found in this remote, remote area. I understand that she was an experienced hiker, experienced hunter. But it's still just, there's so many questions. And that's the problem right there when there's so many questions, that lack of filling in the blanks leads to

other questions, conspiracy theories. So, and the fact that there are other missing scientists from the area and the government, there's just a lot, a lot of questions that I have, you know, surrounding this. Does it make you think that it's possible someone dropped off her remains, that she was killed or died somewhere else and that the remains were transported there and left there because that's a theory that's come up. Yeah, listen, at this point, like I've said before with you, like as a good case agent, you never say this is not possible. You can't say this isn't going to.

So anything is possible as far as, you know, whether somebody brought her. But, you know, based on how it's described that you just read, it's. seems like she was sat up there in this position, not her body dumped. You know, if somebody, you know, was kid. And the fact that you have a, uh, appears to be a bullet entry hole in her lower rear ahead and the exit in the top of her head. Again, you know, the conclusion was that it appears to be a, a bullet that was, that killed her. But the manner, whether it's homicide, suicide that was inconclusive. So is it possible that someone brought her there and placed her there?

That's a long way to carry a body. That's a long way to carry, you know, just to put it in a remote location. A lot of people that if you're going to conduct a homicide, it's dumped the body or bury it in a shallow grave because you want to get it, you know, get rid of the evidence quickly. And if somebody wanted to murder her and they're not going to transport her dead body all the way across, you know, this area from the nearest point. I hope the investigators, you know, from what we've understood, the initial evidence response team left a lot of evidence behind, which was discovered by a private investigator, and then they turned that additional

evidence over. So it seems to me that the team, the crime scene, you know, team that came out from New Mexico State Police really didn't do a good job. So it also tends me to believe that maybe they didn't look at see if there was somebody who tracked it in. I know it's been over a year, but still there could be physical evidence that the individual leaves when bringing in a body. So to answer your question in a long way, I think that she probably died there, you know, in that place and, you know, either whether she was killed or suicide. Let's get into it a little bit more.

So here's what they found when they got there. Quote, the skeletal remains were leaned back against stone in a depression in rocks, the left tibia, fibula, shoe, and sock approximately 20 feet away, there was a firearm near the body. FDMI Martinez noted that the left hand and left foot were absent, and also noticed the remains appeared to show signs of predation. Okay, so there's a question now, obviously, why do you have missing body parts? Is it possible that animals, scavengers in the area did something, or is the missing body parts somehow connected to her death in some way, or the cover-up of her death in some way?

Because you also find the firearm near the body. What stands out to you? I think that for me, the most logic, you know, when conducting an investigation, I go with what's the most logical, and I work off of that. I don't discount anything else. But I would say the most logical is that an animal probably took away small body parts, and that's the foot is also 20 feet away, that to me I would lend that to be the direction of,

most likely as an animal took her body parts, you know, and was, was, you know, eating it or whatever, because this body had been, you know, had been gone for almost a year, so no one had seen it. And it was severely decomposed, almost to the point of where there was almost no skin or barely anything for, you know,

the medical examiner to determine if there was gunshot residue on her hand. There was no, there's nothing for them to test, to see if it was a self-immonauter. inflicted gunshot wound. And the fact that the gun is still there, again, that's great, but without the projectile, which apparently was not located in her skull. So where is the projectile? So this is where the investigator should have gone back out there and tested and conducted a grid search.

Listen, you're looking for a small, single round. It's going to be very difficult to find it, but at least that would be able to match the bullet to the gun. Without that bullet, without the round, you can't say that that gun was the murder weapon or the suicide weapon, or however you want to call it. But again, those are all parts of the test that hopefully New Mexico State Police is doing. Let's get to what everybody's been waiting for, right, the actual cause of death. So here's what the report says about the trauma. There is projectile trauma to the cranium. The projectile entered the cranial base from the right side, damaging the left interior side of C1.

and the left side of the foreman magnum. The angle of entry was from right to left, inferior to superior, and slightly posterior to anterior. The projectile passed through the left petrus portion and exited the cranium through the squamous portion of the temporal bone. Okay, can you walk us through what's significant about this?

Because again, what we're trying to determine is what happened to her. And we don't have a massive. manner of death, right? They listed, the medical examiner couldn't determine if this was homicide, suicide, accident, even though there's, appear just to be a gunshot wound and the firearm is nearby. What do you make of this? I mean, what should we be understanding about what they determined here? Well, there's a lot of questions as to the direction and the round of the travel, even then it moves and how this would have conducted. But one has to think about it is when you're trying to be, if someone is suicidal,

someone wants to take their life and they're conducting a self-inflicted gunshot wound. What is the two most likely that, you know, you're going to see either put it in your, under your chin, under your in your mouth, or sometimes, you know, your forehead? I think that this angle is awkward enough to me, to say, listen, this is where, again, where I conduct my investigations, I conduct my investigations as to looking at all possibilities, but the most likely is the direction I'm going. this right here is not a normal path for for a self-inflicted gunshot wound it wouldn't be normal is it impossible no it's not impossible but for me so then i would be leaning in the direction of that this is a homicide because of the direction of travel the entry the movement of the bullet again someone will be committing suicide they're just distraught all they're going to do is put it under their chin like they see in the movies or they read in the books so those are the things that would be most like If I saw the round here or if I saw the round here in my head, then I'd be like, okay, that's, that's, that would be, would lead me in that direction. But this right here, the description of how the bullet entry and exited, take, you know, hitting part of C1, you know, the upper spine. I think these all leads would lead me as the investigator in the direction of that this would be, you know, appears to be a homicide, that someone killed her. And then that would begin the reasoning as to why.

So we need to figure out motives, who is likely. You have family, coworkers, things that maybe it was a random individual who was, and she was just sitting there lying there and a random individual came up and randomly killed her. That's even possibility there. But then you would say, okay, why is the, why is the, the, the, the revolt, you know, the gun there? Would a, would a killer really be that? So there's lots of questions. and with the failure of answers to these questions,

you're going to have lots of theories and have conversations just like this. And until New Mexico law enforcement authorities really get into the meat and potatoes of the investigation and figure out what's going on with the lack of information that you're going to find, you're going to find a lot more questions. But here's the thing is, with it not being considered

a suicide by the medical examiner, law enforcement in New Mexico has to, to move forward that it is possibly a homicide. So hopefully they are putting weight behind it and saying, okay, this could be a homicide investigation and they're not just discounting and saying, okay, it's suicide. Let's wrap it up. Somebody might say, how's it possible, right? How's it possible they can't determine this? Well, I want to read again from the report directly. It says, given the state of the body's advanced decomposition and paucity of information available at the time of the writing in this report regarding the circumstances of her death, the manner of death is certified as

undetermined. Now, something to mention, the family hired their own search team. They found evidence that law enforcement apparently missed. So I want to read you this from the autopsy report. Quote, on June 24th, 2026, I received an infant body bag from FDMI Martinez at the OMI front desk. FDMI Martinez and NMSP agent Mata had gone to the office of an attorney in Albuquerque who had received additional remains from a private detective in Taos, who had searched the scene after the recovery. team had left. So the family search team apparently found this additional potential evidence that was turned over to the medical examiner weeks after the initial discovery. Few things here. One, so now you're talking about the decomposition, how it might limit your understanding of what

happened to Melissa. But at the same time, it seems concerning that there was evidence found at a crime scene or potential crime scene after law enforcement. had already left, no? No, it's incredibly concerning. Listen, I don't know if the evidence, the physical evidence was found 10 feet away, 15 feet away from the body, but from my understanding is the family was told

by the state entity, whether it be state police or whoever was the crime scene, the scene has been released, here was the location of her body, you can go visit, and then while they were visiting, they were finding additional physical evidence. And that's incredibly disturbing, incredibly disturbing. incredibly disturbing to find that to, A, I would say traumatic to the family that they're finding

not only additional physical evidence, but possibly body parts that they're recovering, but that causing question as to the validity and the sanctity of the initial search team of how much effort did they put into it? I'm glad that the family brought in their own team, their own private investigator to look over this. And from, you know, I've seen reports where, you know, and where I've listened to him speak where he's extremely experienced. and I'm glad he did this, he found this, but, you know, and I echo his, his statements of that that is disturbing to find that you finding additional and not just one or two or multiple pieces of physical evidence that are found on scene at a possible murder scene. You can compare this to other

scenes of you would never just release a scene without completely thoroughly reviewing the area and scouring the area. And I understand. I understand that is physically very, very tolling, for the team to hike up there with the equipment that they had to have. And I'm sure that they were exhausted. I'm sure that they were at their limits. But that doesn't excuse it. That doesn't give you an excuse of missing physical evidence. They should have taken their time, gone it over.

Make sure the scene is secure. Set up a perimeter, whether it be a few hundred yards in each direction, and make sure that you have everything. And then once that's done, go over it again. Again, I've done, I've worked numerous evidence scenes on my case. and supporting other cases, you go over everything with a fine-tooth comb and make sure that you've got everything. This wasn't a little piece of fiber or things. This was significant evidence that was best.

And I want to read one more piece from the report about what was actually found, and we can try to make sense of it. Quote, the remains received on June 24th, 2026, included the shafts of the left radius in ulna, shafts of two metacarpals, and a few small bone fragments. The remains recovered on July 2nd, 2026, included cervical vertebrae 2 to 5 and much of the left foot. Wow. And we also know that the family's attorney, that there was shredded paper, hair, clothing with possible blood, all of that recovered seemingly by the family's private search team. Yeah. And that's what I'm saying is this is not just that piece of paper.

There was physical evidence, bones. biological evidence, blood-stained clothing. There was clothing that could have gunshot residue on it, could show that, you know, whether it was a piece of clothing on her leg that, you know, will show gunshot residue. Everything is part of the picture that those investigators want to paint of that scene. Everything is part of the scene. And there's nothing that should have been discounted, especially bones, especially her body. Like I said, the trauma that her family must have have suffered seeing that there was still parts of her body left behind. And I would be unbelievably incensed at the New Mexico law enforcement authorities that conducted the search. I'd be furious

as a family member, but then also as an experienced case agent, I would be furious at them for failing to collect all the evidence and taking their time to properly do it and that my team was required to. So from here on out, the problem is this. And just like with anything else that we all do, If you've run into a problem from here on out, how can you trust that everything's being done correctly? Okay, if you failed at something simple like picking up pieces of evidence, how are you knowing, you know, you're going to get, you're making sure the detectors are doing everything. So I absolutely concur that the family have their own private team there. And hopefully that private detective is able to get access to some of the information, some of the evidence that they can review it. Obviously, they won't get access to the files, but working as best as they can to make sure that this,

is properly addressed. I want to get to two more points about this. So the toxicology testing on this what appears to be brain tissue came back with the possible presence of marijuana, although I should say that the result was only a preliminary screening. It was never apparently confirmed with more specific testing. There's also a question of the effect of decomposition. The handgun was reportedly registered to Melissa Cassius' husband, Mark Casillas. This is according to the crime junkie podcast. Los Angeles Magazine, they reached out to authorities to confirm that. And I also want to make one other thing clear. So Melissa Cassius' paternal side of the family, they issued a statement. They don't believe that she died by her own hand. They basically said, we want to make something

very clear. The Mondragon family and Melissa's closest friends do not believe Melissa, took her own life. Those who knew and loved Melissa know how deeply she loved her daughter. From the very beginning, her family has maintained that Melissa would not willingly leave her daughter behind. You made a great point, right? The idea of how do we trust this investigation moving forward? Where should it move forward? And are you troubled that we don't have precise answers at this point? Well, I think one of the problems is the time that has passed from the investigation, obviously the body, you know, a dead body will provide in order an amount of clues as to what happened to the person. Even a buried body that is underground by

six feet will retain a lot of the physical evidence. I've been there. I've dug up a body that was six feet deep in New Jersey that would have been murdered by MS-13 and it was a treasure trove of evidence. Even though I've been buried for a number of weeks, not, you know, comparing this to a year, but this body was outdoors for a year, obviously probably was attacked. by some animals. But there's also the cell phone data. So supposedly her cell phones were completely wiped clean of all data, all information, which their family says that's not normal. And we all live and die by our phones these days. Why would her cell phone be erased? Why would she do that? So there's a lot of questions. This isn't just like she went out for a hike and either killed herself or worse killed.

There's more to it. The fact that her phone... Do you think this puts pressure on them to continue the investigation? Should they make a formal announcement? We're continuing this. investigation. We, I mean, I feel like they have to, given how much attention. There's, there's too many, listen, if you have just the body, um, again, that would be suspicious to me. I would have been moving forward. The fact that you have the additional suspicion of the phones being wiped, you know, hers being seen walking on the road, not in her normal, you know, day to day life that she would. Something happened where it deviated, whether she was told to deviate or she self-deviated, there's something there, which means is without those clear answers,

the law enforcement entities cannot say definitively that it was suicide. They have to say, they have to go in the assumption. This is possibly a homicide. And that's absolutely the way they should be moving forward. Unbelievable. Yeah, it's hard to make sense of this. Daniel Bruner, thank you so much for coming on. I was looking forward to having an opportunity to break down this report with you to try to make sense of it.

Always appreciate your insight. My pleasure. Anytime, Jesse. And that's all we have for you right now here on Sidebar, everybody. Thank you so much for joining us. And as always, please subscribe on YouTube, Apple Podcasts, Spotify, wherever you should get your podcasts. You can also check us out on NBC's Peacock as well. If you want to follow me, X Instagram, My News Nation show, Jesse Weber Live, Monday through Friday, 11 p.m. Eastern.

See you next time, everybody.