Nancy Guthrie Update: The One Thing Nobody Is Talking About

When it comes to the Nancy Guthrie case, everyone is focused on the DNA. From the lab in Florida to the degregation and the mixture. Everyone wants to know whether investigators will crack the sample wide open and finally put a name to whoever walked up to Nancy Guthrie's door that night. But according to forensic experts who have been dissecting this case in real time, the DNA may be the least of the investigation's problems. Because before a single sample ever made it to a lab, something went wrong. Something that no amount of sophisticated technology can fix: The crime scene was lost.

"It's Been an Absolute Joke"

From the moment investigators cleared the property, the scene began to die. Journalists walked the grounds. YouTubers followed. Pool maintenance workers showed up. Landscapers. Pizza deliveries. A home health attendant. According to forensic death investigator Joe Scott Morgan, host of Body Bags and a man who has spent a career working alongside medical examiners in some of the most complex death investigations in the country, what happened outside that Tucson home in the early days of this investigation was a forensic catastrophe.

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Authorities are asking the public not to place food delivery orders to the area of Nancy Guthrie's home, as an ABC15 crew spotted a pizza delivery driver walking up to her front door earlier today.

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"It's been an absolute joke," said co-host Josh Seaman on a recent episode of True Crime with the Sarge. Morgan didn't disagree. In any properly managed major crime scene, Morgan explained, the protocol is ironclad. You secure not just the home but the surrounding property. You establish a command post. You put a gatekeeper at the perimeter — one person whose sole job is to log every single individual who crosses that line. Name, time in, time out. No exceptions. Not for the sheriff. Not for the chief. Not for anyone. "If you're paying to see the Rolling Stones," Morgan said, "you don't want to hear the Soggy Bottom Boys. Once it's the Stones, it better by God be the Stones. No one else is allowed in. Period." That's not what happened here.

The Gatekeeper That Wasn't There

At the center of this problem is a concept that most people outside forensics have never heard of: the crime scene log. Every person who enters a secured crime scene leaves a trace. Locard's Exchange Principle — the foundational law of forensic science, established over a century ago — states that every contact leaves something behind. Skin cells. Hair. Fibers. Footprints. DNA. Which means that every unauthorized person who walked that property after Nancy Guthrie disappeared potentially deposited their own biological material into what investigators now hope is a pristine crime scene.

"I don't see a gatekeeper," Morgan said. "There was nobody there as far as I'm concerned." And without a log, without documented control of who came and went, investigators are now faced with a problem that no lab in Florida can solve: they can't prove where the DNA they collected actually came from. The DNA they're counting on to break this case open could belong to the pool guy. It could belong to a landscaper. It could belong to a journalist who got too close. It could belong to a volunteer searcher who tossed their gloves on the ground — and investigators reportedly found nine pairs of discarded search gloves on or near the property, with no clear accounting of who left them. "Any defense attorney," Morgan warned, "would totally destroy this case at this point."

DNA Confetti

Here's what makes this even more precarious. The DNA recovered in the Guthrie case has been described by sources as low-level, degraded, and a mixture — meaning it likely contains biological material from more than one person, commingled in a sample that is already fragile. Morgan calls touch DNA — the kind shed passively through dead skin cells as a person moves through a space — "DNA confetti." It drifts. It settles. It lands where the wind takes it. And because the cells are already dead when they leave the body, the DNA strand inside them is incomplete — a partial profile that requires painstaking, time-consuming laboratory work to interpret.

"The beauty of the fact that ten years ago we probably wouldn't have been able to pick up on co-mingled DNA," Morgan explained. "The equipment is so sensitive now. But it's a double-edged sword. Now you're picking up on it, but how are you going to interpret it?" The lab in Florida is reportedly working to separate out the individual contributors within a mixed, degraded sample. It is, Morgan suggested, an extraordinarily complex task. And it comes with a danger that nobody wants to say out loud: the possibility of burning through the sample entirely before a usable profile can be extracted. "You want to be very, very careful with it," Morgan said. "And then the complexity of co-mingled DNA makes it even more problematic. Not only do you worry about burning through it, you have to save a little bit. Because if you can't solve this right now, you're going to have to wait for the technology to change."

The Septic Tank Moment

Morgan also highlighted what many viewers clocked in real time: investigators examining the septic tank on the property with no gloves, no shoe coverings, leaning over the edge while a body may have been inside. "If you're talking about deposition of DNA — literally taking somebody and pushing them down there — as they make contact around that ring going in, that would be a prime location," Morgan said.

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Sunday morning Pima County Sheriff's Deputies were back at Nancy Guthrie's home. ABC15's drone captured investigators probing what looks like a septic tank in Guthrie's back yard one week after she was reported missing. The investigators searched for a little less than an hour before leaving. 

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"I kind of felt like they were box-checking. We have a list here. Let's go down and check that." His recommendation is to drain it. Get a truck out there, pull every drop, and process it properly. Don't probe it with a pole while contaminating the rim with your own biological material and then walk away.

What Happens Now

The troubling reality, Morgan and his colleagues concluded, is that cases are made or broken in the first 24 hours. The initial stages of evidence collection — the frantic, adrenaline-fueled hours when first responders are clearing rooms and detectives are trying to understand what they're looking at — are when the most critical decisions get made. And in those hours in Tucson, the decisions that were made may now be impossible to undo.

The DNA is still in Florida. The mixture is still being unspoiled. And somewhere out there, a defense attorney is already building the argument that whatever comes back from that lab is meaningless — because the chain of custody was broken before it ever began, and the scene that produced it was walked through by half of Pima County before a single sample was properly secured.