Bone discovery not linked to Guthrie case

The Tucson Police Department confirmed a human bone that was found Thursday morning near North Craycroft and East River roads.

"This will be a prehistoric anthropological investigation," said James Horton, a spokesperson for the Tucson Police Department. "This is not a criminal investigation."

Tucson police were assisted by the University of Arizona's Anthropology Department and the Pima County Office of the Medical Examiner, Horton said.

The bone was found by a streamer who runs a YouTube channel called A.J.DoubleU News. The discovery came just as the investigation into the disappearance of 84-year-old Guthrie surpassed the three-month mark. The Pima County Sheriff’s Department said the investigation remains active.

Guthrie, the mother of "Today" co-host Savannah Guthrie, was reported missing from her home in the Catalina Foothills neighborhood north of Tucson on Feb. 1 and has not been seen since.

What were the breakthroughs in the Guthrie case?

Guthrie was last seen the night of Jan. 31, after being dropped off at home by a relative. She was reported missing the following day when she did not show up at a friend’s home to watch a virtual church service.

The case has had a few breakthroughs, and some dead ends.

During the early days of the investigation, investigators determined she had likely been abducted in the middle of the night.

Investigators said that drops of blood found on the ground in front of Guthrie's front door belonged to her.

DNA found on her property was mixed, meaning it came from more than one person. That makes it harder to run through national databases, said Pima County Sheriff Chris Nanos in an interview broadcast Feb. 21.

The first big breakthrough in the case occurred on Feb. 10 when the FBI released video and photos of a masked man wearing black gloves tampering with Guthrie’s front door camera.

The FBI estimated the man is 5-9 to 5-10 tall with an average build. He was wearing a black, 25-liter Ozark Trail Hiker Pack backpack, which is sold exclusively at Walmart.

In March, authorities found that black gloves thought to be from the kidnapper, and found 2 miles from Guthrie's home, belonged to a restaurant worker not connected to the case, according to DNA results.

NewsNation reported in April that the FBI was analyzing new evidence that included hairs found in Guthrie’s home, according to a source close to the investigation.

The Sheriff’s Department on April 16 referred to its DNA analysis process.

“The private lab we utilize in Florida continues to share information with the FBI lab and other partner labs across the country. DNA analysis remains ongoing.”