Investigators continue to search for Nancy Guthrie, the 84-year-old mother of “TODAY” co-anchor Savannah Guthrie, whose disappearance has transfixed the nation.

Guthrie was reported missing Feb. 1 from her home near Tucson, Arizona. She was last seen the previous night around 9:45 p.m, according to Pima County Sheriff Chris Nanos.

Authorities have described the case as a possible kidnapping or abduction, but clues have been scarce.

Ten days after Guthrie was reported missing, the FBI recovered chilling doorbell camera images of an armed and masked man outside her home on the morning of her disappearance. The FBI has since described that man as a suspect.

Here’s an overview of the key facts in the case.

The timeline of Guthrie’s disappearance

Guthrie visited her daughter Annie Guthrie’s house on Jan.…