The mysterious disappearance of Today show host Savannah Guthrie's mother is now being investigated as a crime, citing "suspicious" circumstances at the 84-year-old's home, authorities said on Monday. Nancy Guthrie was last seen around 9:45 p.m. Saturday at her million-dollar home in the rural Catalina Foothills area near Tucson.
Pima County Sheriff Chris Nanos said at a press conference that officials came across a "very concerning" scene at the home. "We know she didn't just walk out of there. She did not leave on her own," Nanos said. It was also revealed on Monday by Jenna Hager, co-host of 'Today'that Nancy is without the essential medication she needs to survive.
Signs of Crime Found at Home

"She is very limited in her mobility," Nanos said — explaining the grandma "could not walk 50 yards on her own. "We believe now, after we process that crime scene, that we do, in fact, have a crime scene, that we do, in fact, have a crime, and we're asking the community's help," Nanos said.
The sheriff declined to explain why investigators believe a crime may have taken place, saying it would be "inappropriate at this time."

Authorities have been searching for Nancy since her family reported her missing late Sunday morning. Officials said she was last seen Saturday night, when at least one of her children dropped her off at her home.
Savannah, who has an older brother and sister, is currently in the Tucson area, they added.
Concern grew Sunday morning after a fellow church member contacted the family to say Nancy had not shown up for services. Alarmed, her relatives then contacted the police.

Nanos said that although Nancy has difficulty walking, she is "of great sound mind." It is believed that Nancy does not have dementia or suffer from any form of cognitive decline.
"This is not a dementia-related ... She is as sharp as a tack. The family wants you to know she didn't just wander off," he said.
"Her physical limits are based on just age."
Race Against Time
Nancy was active on social media, with her last post being an anti-ICE message she reshared on Facebook on Jan. 27. Police said they now have her cellphone and are carefully reviewing it for any clues that might explain her disappearance. Authorities and family members say the search has become a race against time, as Nancy depends on daily medication to survive.

She "is in need of medication, medication that if she doesn't have it in 24 hours, it could be fatal," Sheriff Nanos said, adding, "Time is very critical."
Authorities are reviewing security footage from the home and have also asked neighbors to check their Ring camera recordings for anything unusual.
When asked whether TV star Savannah Guthrie had received any threats, Nanos said, "We've spoken with her, and we'll continue to follow up on that."
"She has a security team that's been in touch with us throughout the night," he said. "But we're not going to dismiss any angles for sure.
"But right now, immediately, we don't know of anything like that.''

Savannah, who became a co-host of 'Today' in June 2011, skipped on Monday's broadcast after her mother's disappearance.
"On behalf of our family, I want to thank everyone for the thoughts, prayers and messages of support," she said in a family statement Monday.
"Right now, our focus remains on the safe return of our dear mom. We thank law enforcement for their hard work on this case and encourage anyone with information to contact the Pima County Sheriff's Department at (520) 351-4900," she said.