TUCSON, Ariz. – Officials in Tucson, Arizona, are continuing to search for the mother of NBC "Today" co-host Savannah Guthrie after she went missing from her home and was last seen on Saturday night, saying that a crime has been committed.

Nancy Guthrie, 84, was last seen at her Tuscon residence at around 9:30 p.m. Saturday, according to the Pima County Sheriff's Department. While officials didn't immediately elaborate on the circumstances of her disappearance, Sheriff Chris Nanos said on Monday that "we do, in fact, have a crime."

A spokesperson for the Pima County Sheriff's Office told Fox News Digital that it's believed Nancy Guthrie was either kidnapped or abducted.

"Sheriff [Chris] Nanos has stated that he believes that a crime has been committed," a spokesperson for Pima County Sheriff’s Office told Fox News Digital. "At this point, investigators believe she was taken from the home against her will and that includes possible kidnapping or abduction."

Nanos said Nancy Guthrie didn't leave the home by herself. According to the 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.

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 Nancy Guthrie "is of great sound mind" besides 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.

The Pima County Sheriff's Office is providing a reward up to $2,500 for information relating to the disappearance of Nancy Guthrie.

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