Pima County Sheriff Chris Nanos stated Tuesday that he remains optimistic the kidnapping of Nancy Guthrie, mother of "Today" show host Savannah Guthrie, will be resolved, even as the case approaches the six-month mark with few leads.

"We have so much in terms of video evidence to look at. So I’m still positive that we’re going to resolve this case," Nanos told NBC affiliate KVOA. He urged anyone with information to come forward, emphasizing that "there’s no lead too small."

Nanos also confirmed that laboratories across the country are collaborating on analyzing DNA evidence. "We’re working this as hard as we can," he stated, echoing Savannah Guthrie’s plea. "We, like Savannah today, we encourage you, if you know something, saw something, please let us know."

Savannah Guthrie issued a tearful video appeal on Monday, directly addressing her mother's abductors. "The world can be a cruel and unforgiving place, and I know that you have tried to do things the right way," she said in the video titled "Bring her home." "So I am asking you, begging you, to do the right thing now." She urged them to "make the right choice" and help bring her mother home, describing her family's ongoing agony and nightmare.

Nancy Guthrie, 84, was abducted from her Tucson home on Feb. 1. Her family is offering a $1 million reward for her return. No arrests have been made in connection with her disappearance.

Reports have emerged suggesting that ransom notes, allegedly sent by the abductors days after Guthrie vanished, contained conflicting information. One note reportedly claimed Guthrie was "safe but scared" and demanded $4 million in Bitcoin, while a second note claimed she had died. Savannah Guthrie has previously described the impact of these reports on her family, stating, "We cannot be at peace."

A federal source close to the investigation told Fox News that Savannah Guthrie had spoken with investigators about the content of her recent video appeal. Monday's appeal marked her first public statement on the case in several weeks.