Testing on a piece of biological evidence taken from the Tucson-area home of Nancy Guthrie has come up empty, Pima County law enforcement officials confirmed, complicating investigators’ efforts in the wider inquiry into the 84-year-old’s disappearance. Sheriff Chris Nanos told reporters that a strand of hair recovered inside the residence did not produce a usable DNA profile when analyzed, leaving detectives without the hoped-for direct genetic link to a suspect.
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"It came back … there’s no DNA," Nanos said in an interview, summarizing the result of the laboratory analysis. He stressed that the absence of a usable profile from the hair sample does not mean it cannot be useful later in the investigation; the physical sample has been preserved. "But does that mean the hair isn’t that of the suspect? We won’t know that till we have the suspect’s hair. You don’t just destroy it," he said. "There’s other things that hair may prove valuable for, but right now it was just about, ‘Is there any DNA there?’ And the answer was no."
Family photograph circulated during the search showing an elderly woman seated next to a younger woman smiling at the camera.
While the strand of hair failed to yield a profile, investigators continue to work on another piece of biological evidence recovered inside the home: a mixed DNA sample that officials say contains genetic material from multiple individuals. Sheriff Nanos described that sample as comprising DNA from as many as four different people, a complexity that has made it difficult to separate and analyze individual contributors.
To address that challenge, multiple forensic laboratories across the country have been enlisted to examine the mixed sample. Those facilities include the FBI laboratory in Quantico as well as forensic labs in Kansas, Florida, California and Arizona. "My understanding is there are at least five, maybe six, labs across the country that are working on all of this," Nanos said. "We have some of the brightest minds in the nation, if not the world, working on all of this."
Law enforcement also confirmed they are employing investigative genetic genealogy techniques in their effort to generate leads from DNA evidence when possible. Nanos said advances in DNA technology have given investigators reason to remain hopeful even as some tests come back without conclusive results. "Anything we can grasp onto with DNA is a part of this investigation," he said. "That’s really where some of my optimism is, that I just know that we’re gonna get this thing resolved."
Night-vision doorbell still showing a masked figure at a front entryway; police say DNA recovered inside the home did not identify a suspect.
Authorities have said the investigation began after Guthrie, the mother of a national television journalist, was reported missing in the early hours of February 1. Doorbell camera footage captured an individual wearing a mask and dark clothing outside the home at the time investigators believe she was taken. The person in the footage appears to be wearing long sleeves, gloves and carrying a black Ozark Trail backpack. Detectives have not been able to confirm whether the person observed on video acted alone. "I don’t think anybody’s here ready to say it’s one guy, it’s 10 guys," Nanos said. "Did he have help? Could have."
Law enforcement has pursued multiple investigative threads since the disappearance, and the public has been asked to provide tips. A combined reward that now tops $1.2 million remains available for information leading to an arrest, and authorities continue to urge anyone with relevant information to contact the FBI, local investigators or to submit anonymous tips through Crime Stoppers. "Somebody in our community, somebody out in this world knows something. Call us, tell us, give us that information. Somebody knows where Nancy’s at. We need their help," Nanos said.
The probe has produced at least one criminal case indirectly tied to the investigation. Federal prosecutors say a California man, Derrick Callella, pleaded guilty earlier in the month to sending harassing communications to the Guthrie family in the form of fake ransom messages that demanded Bitcoin. Authorities emphasized Callella is not believed to have been involved in the alleged abduction itself; rather, prosecutors said he took advantage of media coverage and the family’s distress. Callella admitted to using a telecommunications device to harass and is scheduled to be sentenced on September 10. The offense carries a maximum prison term of two years, though under the terms of his plea agreement he could receive probation instead.
Despite the hurdles in the forensic work and the lack of an arrest to date, investigators say they remain committed to following every lead and continuing laboratory analysis. Nanos reiterated that multiple laboratories and experts are examining the evidence and that the preserved hair and mixed DNA are being retained for potential future use. Meanwhile, the Guthrie family has continued to ask for privacy as they press for answers, and the elder woman’s daughter has taken steps to step away from her professional duties temporarily while the investigation continues. The sheriff said that while results have been mixed, the work underway — and the expanding investigative tools available to modern forensic teams — leave officials feeling that the case can still move forward toward resolution.
Growing frustration with the investigation's handling has been voiced online, including by commentator @GuntherEagleman who cited legal analyst Donna Rotunno's surprise at the delayed disclosure of the hair results and FBI Director Kash Patel's comments on missed opportunities for earlier Quantico lab involvement that could have preserved more evidence.
The FBI’s Phoenix office told NBC News that, after its review, “all hair had been resolved and it does not point to a suspect,” a statement that law enforcement said complements the sheriff’s announcement that the preserved hair yielded no usable DNA profile.
Federal court records and local reporting show that the California defendant, Derrick Callella, was ordered from the courthouse into immediate residential drug treatment ahead of his September 10, 2026, sentencing after admitting recent drug use and breaking bond conditions.
Prosecutors and investigators said the harassing ransom-style communications were traced to a VOIP number and to an IP address linked to Callella’s residence, which helped federal agents identify and charge him in the separate harassment case.