More than 100 days after 84-year-old Nancy Guthrie vanished from her Tucson, Arizona, home, Pima County Sheriff Chris Nanos says crime labs, including the FBI's facility at Quantico, are narrowing in on the source of unidentified DNA tied to blood evidence found at her property.
Nanos told People in a recent interview that investigators have not yet named a suspect but are making progress on the forensic front. The case has drawn national attention in part because Nancy Guthrie is the mother of NBC Today anchor Savannah Guthrie.
Police believe the elderly woman was abducted from her home on February 1. Blood spatter was found on the front porch and along the pathway leading to the street. Doorbell camera footage captured a masked individual near the property, and investigators released both the footage and a description of the suspect. No arrests have followed.
Nanos struck a cautiously optimistic tone, insisting the investigation has not stalled. He told People:
"I know we have DNA that is unknown who the contributor or depositor is, but I think they're getting closer to finding out who that was."
DNA samples are being processed at multiple laboratories across the country, Nanos said, including the FBI's high-tech lab in Quantico, Virginia. He expressed what he called "confidence in our labs" and drew a clear line between an active case and a cold one.
"When the labs tell us, 'Hey, there's nothing else we can do,' well, then maybe we've got a problem... we've got a cold case... but right now, the labs aren't telling us that."
That distinction matters. A cold case designation would signal that investigators have exhausted their leads. Nanos went out of his way to say the opposite, that the country's best forensic resources remain engaged.
Nanos acknowledged public frustration with the pace of the investigation but pushed back against pressure to rush toward an arrest. The sheriff framed the deliberate approach as a matter of constitutional duty.
"Nobody wants to make a false arrest. Nobody wants to falsely accuse somebody. At some point in time, someday we may have somebody in a courtroom that deserves his or her right to have a fair and impartial trial. The way you get that is through a fair and impartial investigation."
It is a statement worth hearing in full. In an era when high-profile cases generate intense media cycles and public demands for immediate answers, Nanos is making the case that solid police work cannot be rushed without risking the integrity of any eventual prosecution. Botch the investigation, and a guilty party could walk free on procedural grounds.
The sheriff put it plainly:
"There's frustration because people want to know. But this is just like any other case. Sometimes you solve them within hours or days. Sometimes it takes a long time."
That is a sober assessment, and one that law enforcement officials across the country have echoed in complex cases where forensic evidence is the primary thread. The FBI's involvement in reviewing suspicious disappearances has become an increasingly visible part of federal law enforcement's portfolio, and the Guthrie case now sits squarely in that category.
The known facts paint a grim picture. Nancy Guthrie, 84, was last seen at her Tucson home on February 1. Blood was found in multiple locations on the property, on the front porch and along the path from the house to the street. That pattern suggests the possibility of a violent encounter and movement away from the residence.
Police released doorbell camera footage showing a masked suspect near the property. The footage included a physical description of the individual, but no name has been attached to the figure on camera. The identity of the masked person remains one of the case's central open questions.
Equally unresolved: whose blood was found at the scene. Nanos confirmed that unknown DNA exists within the evidence, but he did not specify whether the blood belongs to Nancy Guthrie, to someone else, or to both. That ambiguity has fueled ongoing public debate about what happened that night.
The sheriff's comments suggest investigators are betting heavily on the forensic path. Multiple labs are working the evidence. The FBI's Quantico facility, one of the most advanced forensic operations in the world, is among them. If the unknown DNA can be matched to an individual in a criminal database, or to a known person of interest, the case could break open.
If it cannot, the investigation faces a harder road. Cases that hinge on physical evidence but lack a DNA match often depend on witness testimony, surveillance networks, or digital forensics to move forward. None of those avenues were addressed in the sheriff's public remarks.
The disappearance of an elderly woman from her own home is the kind of crime that shakes a community's sense of safety. When that woman's daughter is one of the most recognizable faces on morning television, the scrutiny intensifies by orders of magnitude.
Pima County's sheriff appears to understand the stakes. His public comments have been measured, focused on process, and careful not to compromise the investigation. That discipline is worth noting. In other high-profile cases, from suspicious death investigations in San Jose to contested federal prosecutions, premature public statements by officials have complicated proceedings and eroded public trust.
Nanos has so far avoided that trap. He has not named suspects. He has not speculated about motive. He has told the public what he can, that labs are working, that progress is being made, and that the case is not cold, without telegraphing details that could compromise a future prosecution.
That restraint will be tested as the days continue to pile up. Over 100 days is a long time for a family to wait without answers. It is a long time for a community to wonder whether the person responsible is still walking free.
The Guthrie case is not unfolding in a vacuum. Across the country, violent crimes against vulnerable individuals, particularly the elderly, continue to demand law enforcement resources that are already stretched thin. The involvement of the FBI's Quantico lab in a local missing-persons case speaks to the seriousness with which federal authorities are treating this investigation.
It also raises a practical question: how long can multi-agency forensic resources remain dedicated to a single case before institutional pressures force a shift in priorities? Nanos seemed to address that concern indirectly when he said the labs have not yet told investigators they have exhausted their options.
Meanwhile, the public's appetite for accountability in violent criminal cases shows no sign of fading. Nor should it. An 84-year-old woman was apparently taken from her own front porch, and blood was left behind. Someone did that. Someone knows who did it.
The masked figure captured on doorbell camera footage remains unidentified. No suspects have been named. The DNA is still being processed. Every one of those facts represents an unanswered question, and a family that has now spent more than three months without their mother.
The integrity of the forensic process matters. So does the handling of FBI evidence in high-stakes investigations. If the labs deliver a match, the next phase, arrest, charging, and trial, will test the entire chain of custody that Nanos is so carefully guarding now.
Nanos expressed confidence that the nation's best forensic minds will deliver results:
"When you have the best minds of the country working on problems, I think they're gonna solve them. It just takes a while."
For Nancy Guthrie's family, "a while" has already been a long time. For the public, the sheriff's assurances will hold only as long as the investigation continues to move forward. The moment it stalls, the moment the labs say there is nothing more they can do, the calculus changes entirely.
The case now rests on the labs. If the unknown DNA yields a match, investigators will have their first concrete lead toward a suspect. If it does not, Pima County will face the difficult reality of a high-profile case with physical evidence but no identified perpetrator.
Nanos has been transparent about that possibility without conceding it. His public posture is one of disciplined optimism, progress is being made, the case is active, and the process must be respected.
That posture is the right one. But posture is not a result. An 84-year-old woman has been missing for more than 100 days. Blood was found at her home. A masked figure was caught on camera. And still, no one has been charged.
The forensic evidence will either speak or it won't. What matters now is that when it does, the investigation behind it is clean enough to hold up in court, because justice delayed by careful work is still justice, but justice lost to sloppy procedure is gone for good.