The embattled sheriff leading the search for missing Nancy Guthrie says he believes she is still alive because he has not seen any ‘proof of death’.

Pima County Sheriff Chris Nanos used the phrase in a new interview with Fox10, hours after his office admitted a glove found two miles from Nancy’s home failed to match suspect DNA found inside her property or to criminal databases. 

Although the failure to match the DNA marked a setback to the investigation, Nanos insisted that his detectives are not losing hope that the 84-year-old could be returned to her family. 

‘They ask me, do I have proof of life? I ask them, is there proof of death?’ Nanos said. 

‘I’m going to have that faith, and sometimes that faith, that hope, is all we have… My team, 400 people out there in the field today, woke up this morning and went out there with the hope and the belief that they’re going to find Nancy.’ 

Nanos, who has come under scrutiny for his handling of the case, said that he is insistent that he will not ‘crush’ the hopes of Guthrie’s family that she is alive. 

He vowed: ‘We’re going to continue working this case, every minute of every day, and we will find her.’ 

Directing his remarks to those responsible for Nancy’s disappearance, Nanos added: ‘And we will find you… to the individual doing this, let her go, just let her go. It will work out better for you in the long run, trust me.’ 

Nancy was last seen on the evening of January 31 entering her home in the Catalina Foothills of Tucson, Arizona. Her pacemaker disconnected from an Apple Watch at her home hours later. 

A glove discovered two miles from her home had been touted as the first major break in the search which has now entered its third week without any suspects or persons of interest being named.

The black nitrile glove appeared to match one worn by a masked suspect seen on Nancy’s doorbell camera just before her disappearance in the early hours of February 1.

But on Tuesday authorities conceded that the glove failed to match both DNA from inside Nancy’s home and the CODIS criminal database – a national archive of all DNA from arrestees nationwide. 

Nanos attempted to downplay the development as a setback to the investigation. 

The sheriff told Fox10 that his detectives have, ‘other DNA evidence from the scene, that is more critical to me than DNA found two miles from the scene’.

‘All of that will still be submitted for further analysis,’ he said. 

‘You take a fingerprint, and you hope to match it right away. But that’s not that easy.’ 

Nanos added that the evidence found at the scene included a mix of several people’s DNA, saying that he had to ‘hope’ that forensics analysis could ‘separate that.’ 

Frustrations surrounding the investigation have heaped pressure on Nanos, who has come under scrutiny for his handling of the case amid allegations he made crucial errors in the first hours of the search.

Authorities said they also uncovered 16 gloves scattered in various locations around the home, most of which were found to belong to investigators combing the scene.

The failure to match the glove to a suspect comes exactly one week after authorities arrested delivery driver Carlos Palazuelos in connection with the case before releasing him without charge just hours later.

His brief detention last Tuesday brought further humiliation as he angrily denied having anything to do with Nancy’s abduction.

On Friday Pima County SWAT officers raided a home two miles from Nancy’s, but no-one was detained.

Around the same time, FBI agents stopped a Range Rover Sport and spoke to its driver, but he too was released without charge. 

The FBI said it has received more than 13,000 tips, while the Pima County Sheriff’s Department reported taking at least 18,000 calls related to the case that have generated between 40,000 and 50,000 leads.

Authorities have also publicly cleared Nancy Guthrie’s family members as possible suspects, calling them victims in the case.

That includes Nancy’s son-in-law Tommaso Cioni, who previously faced unfounded online speculation about whether he was involved in the disappearance.

In a video message posted to Instagram on Sunday night, Savannah pleaded directly with whoever may be holding her mother.

‘It is never too late to do the right thing,’ Guthrie said. ‘And we are here. And we believe in the essential goodness of every human being, that it’s never too late.’