Arizona Sheriff Warns DNA Tech Issues May Delay Nancy Guthrie Case

Pima County Sheriff Chris Nanos says mixed DNA evidence is challenging investigators

Feb. 22, 2026 at 7:24am

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Pima County Sheriff Chris Nanos says the investigation into the disappearance of 84-year-old Nancy Guthrie from her Tucson, Arizona home is facing challenges due to mixed DNA evidence found at the scene. Nanos told NBC Nightly News that the lab his department is using is struggling with the advanced DNA technology, and it may take "weeks, months, or maybe a year" to resolve the issues. The sheriff noted investigators are still pursuing other avenues of the investigation, but the DNA evidence is proving difficult to analyze.

Why it matters

The Nancy Guthrie missing persons case has garnered national attention, and the sheriff's comments highlight the technological hurdles law enforcement can face when dealing with complex forensic evidence. The case also raises questions about the capabilities and limitations of modern DNA analysis, especially in time-sensitive investigations.

The details

According to Sheriff Nanos, the DNA samples recovered from Guthrie's home contain DNA from more than one person, making it harder to run the evidence through national databases. The sheriff said his department is using a lab in Florida, but the technicians there are struggling with the advanced DNA technology involved. Nanos stated that the lab has told him "the technology is moving so fast and in such a frenzy that they think some of this stuff will resolve itself just in a matter of weeks, months, or maybe a year."

  • Nancy Guthrie was last seen on the night of Saturday, Jan. 31, 2026, after being dropped off at her home in the Catalina Foothills area near Tucson.
  • It has been several weeks since Guthrie's disappearance, and no arrests have been made.

The players

Chris Nanos

The Pima County Sheriff leading the investigation into Nancy Guthrie's disappearance.

Nancy Guthrie

An 84-year-old woman who went missing from her home in Tucson, Arizona on January 31, 2026.

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What they’re saying

“Our lab tells us that there are challenges with it. The technology is moving so fast and in such a frenzy that they think some of this stuff will resolve itself just in a matter of weeks, months, or maybe a year.”

— Chris Nanos, Pima County Sheriff (NBC Nightly News)

“It's never fast enough for the Sheriff. I want it like you. Come on, guys, let's go. Let's go, let us find her. But the reality is, I also know that sometimes things take time.”

— Chris Nanos, Pima County Sheriff (NBC Nightly News)

What’s next

The judge in the case will decide on Tuesday whether or not to allow Walker Reed Quinn out on bail.

The takeaway

This case highlights the challenges law enforcement can face when dealing with complex forensic evidence, especially in time-sensitive missing persons investigations. The limitations of current DNA analysis technology are exposed, raising questions about how to best utilize these tools to aid investigations while also managing public expectations.