Nancy Guthrie Case: Sheriff Chris Nanos Shares Update On Mixed DNA Findings

One month after Nancy Guthrie vanished from her home in Tucson, Arizona, investigators are still working to extract a usable DNA profile from evidence collected at her property - and so far, the FBI database has come back empty.

Pima County Sheriff Chris Nanos confirmed the forensic difficulty in an interview with NBC News correspondent Liz Kreutz on 2 March, telling her he still believes his team is making progress.

Guthrie, 84 and the mother of Today show anchor Savannah Guthrie, was last seen on the night of 31 January at her home in the Catalina Foothills area near Tucson. Her family reported her missing the following morning. Authorities have been treating the case as an apparent abduction.

The DNA recovered at the property is a mixed sample, Nanos told Kreutz, meaning it likely contains biological material from more than one person. Forensic experts have previously noted that mixed profiles are notoriously difficult to untangle, often requiring extended laboratory work before any individual contributor can be identified. Portions of the sample have been submitted to the national FBI database. No matches have been returned.

Nanos said he still considers the DNA a viable lead. Getting there will simply take more time, he told NBC News.

Backpack Trail and Camera Footage Yield No Confirmed Leads

The doorbell camera footage that authorities released publicly last month remains one of the most scrutinised pieces of evidence in the case. The footage shows a figure standing outside Guthrie's home wearing a ski mask, a holster, and a backpack.

Investigators confirmed the backpack is an item sold exclusively through Walmart, but Nanos told Kreutz that does not necessarily establish where it was purchased. 'We've now learned that maybe it wasn't purchased out of Walmart,' he said. 'That backpack is new, it's exclusive to Walmart, but who's to say I didn't buy it and put it on eBay? That's what we're looking at.'

Investigators have also been unable to identify the clothing worn by the figure in the footage.

Separately, Ring camera footage obtained by Fox News Digital captured a vehicle travelling past a property approximately 2.5 miles from Guthrie's home at 2:36 a.m. on 1 February - the same morning her family filed the missing persons report.

NBC News said it had not been able to independently verify the footage. Nanos confirmed his office is aware of it. 'We're aware of it, and we're looking into it, just like any other piece of evidence,' he said, adding that authorities are reviewing that vehicle alongside hundreds of thousands of others recorded in the area at that hour.

Nanos also said investigators are not currently looking at any new names, a statement that ran counter to accounts from some local Tucson businesses who told media outlets they had been shown photographs and a list of individuals by the FBI.

Homicide Unit Joins Search as Family Marks One Month

The sheriff's department has assigned a dedicated team from its homicide division to work alongside FBI agents on the investigation. Nanos said his office is pursuing thousands of tips and is still operating on the belief that Guthrie is alive. 'I think the investigators are definitely closer,' he told Kreutz.

He acknowledged there is information his department is choosing not to release publicly. 'There's so much that everybody wants to know, but I would be very neglectful, irresponsible as a police, law enforcement leader, to share that with everybody,' he said.

On 2 March, the same day as Nanos' interview, Savannah Guthrie, her sister Annie, and Annie's husband Tommaso were photographed placing flowers and a handwritten card at a memorial that has grown outside Nancy Guthrie's home. The message on the card read: 'Though we are surrounded by so much darkness and uncertainty, our love burns bright. We love you Mommy. We miss you so much.'

Savannah posted a photograph of yellow flowers from the memorial to Instagram. 'We feel the love and prayers from our neighbours, from the Tucson community and from around the country,' she wrote. 'Please don't stop praying and hoping with us. Bring her home.'

The family is offering a $1 million (£790,000) reward for information leading to Nancy Guthrie's whereabouts. Anyone with information is asked to contact the Pima County Sheriff's Department.