TUCSON, Ariz. – Authorities in Tucson, Arizona are intensifying their efforts to locate the mother of Savannah Guthrie, co-host of NBC’s “Today,” who vanished from her home on Saturday night. Officials have confirmed that a crime is involved in her disappearance.

Nancy Guthrie, aged 84, was last seen around 9:30 p.m. Saturday at her Tucson residence, as reported by the Pima County Sheriff’s Department. Although details about the nature of her disappearance remain sparse, Sheriff Chris Nanos stated on Monday, “We do, in fact, have a crime.”

Nanos further disclosed that Nancy Guthrie did not leave her home of her own accord.

On Monday morning, Savannah Guthrie shared a heartfelt message with NBC’s “Today.”

“On behalf of our family, I want to express gratitude for the thoughts, prayers, and messages of support. Our primary focus is on ensuring the safe return of our beloved mom,” the statement read.

Savannah Guthrie and her mother, Nancy Guthrie. (Instagram/Savannah Guthrie)

Here’s a timeline of events:

Saturday 9:45 p.m.: 

The Pima County Sheriff’s Department says Nancy Guthrie was last seen at her residence near East Skyline Drive and North Campbell Avenue on Saturday evening. Nancy Guthrie’s children dropped her off at the home at around 9:45 p.m. on Saturday, Pima County Sheriff Chris Nanos said.

Sunday 11:00 a.m.: 

Nanos said that Nancy Guthrie didn’t attend her church service, adding that her family was notified about the absence by a churchgoer. Officials said family members went to Nancy Guthrie’s home at around 11 a.m. and spent some time looking for her.

Sunday 12:00 p.m.:

Nancy Guthrie’s family calls 911, according to officials.

Savannah Guthrie and her mother, Nancy Guthrie. (Instagram/Savannah Guthrie)

Savannah Guthrie and her mother Nancy Guthrie appear with Jenna Bush Hager on “Today” on Wednesday, April 17, 2019. (Nathan Congleton/NBCU Photo Bank/NBCUniversal via Getty Images)

Sunday afternoon/night: 

The Pima County Sheriff’s Department begins search and rescue efforts using helicopters, infrared cameras and drones to search for the missing 87-year-old. During a news conference on Sunday night, Nanos said they found evidence that raised “some concerns” at Nancy Guthrie’s home.

“We’re pretty much just throwing everything at this that we can. Guthrie is 84 years old and is not of good physical health, and so naturally that’s a great concern,” Nanos said. “This is very concerning to us. We don’t typically get the sheriff out at a scene like this. But it’s very concerning what we’re learning from the house.”

Savannah Guthrie and her mother, Nancy Guthrie. (Instagram/Savannah Guthrie)

Monday:

Nanos said during a news conference that Nancy Guthrie didn’t leave the house on her own accord, adding that a crime has been committed. He said that the search and rescue mission has been shut down to give that team time to rest.

“We believe now, after we processed that crime scene, that we do, in fact, have a crime scene that we do, in fact, have a crime,” Nanos said. “She did not leave on her own. We know that.”

“We don’t see this as a search mission as much as we do a crime scene,” he added.

Savannah Guthrie and her mother, Nancy Guthrie. (Instagram/Savannah Guthrie)

Australian-born presenter Savannah Guthrie poses alongside her mother Nancy Guthrie during a production break while hosting NBC’s “Today Show” live from Australia at Sydney Opera House on May 4, 2015, in Sydney, Australia. (Don Arnold / Wireimage)

Nanos noted that Nancy Guthrie has limited mobility and has medication that she needs to take every 24 hours, which could be fatal if not taken. He said that Nancy Guthrie “is of great sound mind” beside her physical ailments, adding she’s “sharp as a tack.”

Investigators were seen in the area where Nancy Guthrie lives, including sheriff’s department helicopters.

“We need her back. We need to find her. and time is very critical. She is 84. She needs her meds,” Nanos said.

People with information about Nancy Guthrie’s disappearance are asked to contact the Pima County Sheriff’s department at: 520-351-4900.