Nancy Guthrie Sheriff Chris Nanos says he's 'still positive' case will be resolved despite long wait

Pima County Sheriff Chris Nanos says he's "still positive" the Nancy Guthrie case will be resolved as investigators continue to dig through evidence more than 25 weeks after her home invasion abduction in Tucson, Arizona.

"We have so much DNA to sort through," Nanos said in an interview aired on "Today."

Guthrie is the 84-year-old mother of one of the show's co-hosts, Savannah Guthrie.

NANCY GUTHRIE'S SUSPECTED ABDUCTION: TIMELINE OF EVENTS IN DISAPPEARANCE OF 'TODAY' HOST'S MOM

"We have so much...