The elderly US woman and mum of TV host Savannah Guthrie has not been seen since January 31.
A glove containing DNA found just over 3km from the house of US Today show host Savannah Guthrie's mother appears to match those worn by a masked person outside her front door in Tucson the night she vanished, the FBI said this morning.
The glove, found in a field near the side of a road, was sent off for DNA testing. The FBI said in a statement that it received preliminary results Saturday and was awaiting official confirmation.
Nancy Guthrie, 84, was last seen at her Arizona home on January 31 and was reported missing the following day. Authorities say her blood was found on the front porch. Purported ransom notes were sent to news outlets, but two deadlines for paying have passed.
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The discovery was revealed days after investigators had released surveillance videos of the masked person outside Guthrie's front door. A porch camera recorded video of a person with a backpack who was wearing a ski mask, long pants, jacket and gloves.
On Thursday, the FBI called the person a suspect. It described him as a man about 1.75m tall with a medium build. The agency said he was carrying a 25-litre "Ozark Trail Hiker Pack" backpack.
Late Friday night, law enforcement agents sealed off a road about 3.2km from Guthrie's home as part of their investigation. A series of sheriff's and FBI vehicles, including forensics vehicles, passed through the roadblock.
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The investigators also tagged and towed a Range Rover SUV from a nearby restaurant parking lot late Friday.
The sheriff's department later said the activity was part of the Guthrie investigation, but no arrests were made.
On Tuesday, sheriff deputies detained a person for questioning during a traffic stop south of Tucson. Authorities didn't say what led them to stop the man, but confirmed he was released.
The same day, deputies and FBI agents conducted a court-authorised search in Rio Rico, about an hour's drive south of the city.
Authorities have expressed concern about Nancy Guthrie's health because she needs vital daily medicine.
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She is said to have a pacemaker and is dealing with high blood pressure and heart issues, according to sheriff's dispatcher audio on broadcastify.com.
Earlier in the investigation, authorities had said they had collected DNA from Nancy Guthrie's property which doesn't belong to Guthrie or those in close contact with her. Investigators were working to identify who it belongs to.
The FBI also has said approximately 16 gloves were found in various spots near the house, most of which were searchers' gloves that had been discarded.
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