What to know about Nancy Guthrie's kidnapping and the race to find her

TUCSON, Ariz. — Authorities on Tuesday detained a person for questioning in the disappearance of Nancy Guthrie, more than a week after the mother of ''Today'' show host Savannah Guthrie was apparently kidnapped from her home in Arizona.

Sheriffs deputies detained the person during a traffic stop south of Tucson, according to the Pima County Sheriff's Department. It didn't immediately provide additional details. It wasn't clear whether the detained person was the same individual who had been captured on surveillance video outside Guthrie's house.

The 84-year-old grandma was reported missing by her family after she didn't attend church that morning, Feb. 1, and authorities say her blood was found on the front porch. Purported ransom notes were sent to news outlets, however two deadlines for paying have passed, with the most recent on Monday.

The family has posted increasingly bleak videos pleading for their mom's return. At first, they primarily asked the abductor or abductors to get in contact and expressed a willingness to pay. But since then, Savannah Guthrie has shifted to asking the public for any information, and on Tuesday asked for help identifying the person in the new surveillance video.

Here's what to know about the case:

Questioning and a search

A few hours after its person of interest announcement, the sheriff's department said it was conducting a court-authorized search of a location in Rio Rico with the help of the FBI's Evidence Response Team.

New videos reveals an armed, masked person

Videos released by the FBI earlier Tuesday show a person wearing a backpack and a gun holster attached to their front waist area walking up to Nancy Guthrie's door. The person's gloved hand uses plants to try to block the camera's view.

Investigators initially said there was no video available since Guthrie didn't have an active subscription to the doorbell camera company — much to the frustration of the country sheriff. But digital forensics experts kept working to find images in back-end software that might've been lost, corrupted or inaccessible, and FBI Director Kash Patel announced they were successful Tuesday.

The images show ''an armed individual appearing to have tampered with the camera at Nancy Guthrie's front door the morning of her disappearance,'' Patel said.

Shortly after the announcement, Savannah Guthrie posted several snapshots the surveillance images with the caption: ''We believe she is still alive. Bring her home,'' with the FBI and sheriff's phone numbers. Within minutes, the post had thousands of comments.

The FBI this week began posting digital billboards about the case in major cities from Texas to California.

Initial pleas to kidnappers

There has been a marked shift in tone throughout the four videos the Guthrie family has released over the course of the last week.

Initially, Savannah Guthrie and her two siblings seemed to be speaking to their mothers alleged kidnapper directly, after multiple media outlets reportedly received ransom notes demanding money for Nancy Guthrie's safe return. Authorities didn't explicitly confirm the authenticity of the notes but said they were being investigated seriously.

There were two deadlines set out in the notes: one for last Thursday and a second for the following Monday.

In the first video released last Wednesday, Savannah Guthrie sat between her brother and sister, and asked potential kidnappers for proof their mother was alive.

''We are ready to talk. However, we live in a world where voices and images are easily manipulated,'' Savannah Guthrie said. ''We need to know without a doubt that she is alive and that you have her. We want to hear from you and we are ready to listen.''

Camron Guthrie, her brother, reiterated that plea in another video Thursday afternoon.

No response from potential abductors

A second email related to Nancy Guthrie's abduction was sent to the Tucson-based television station KOLD on Friday afternoon, prompting a third video from the Guthrie family on Saturday.

But two days later, she struck a bleaker tone, appearing alone and speaking directly to the public, not the abductor.

''We are at an hour of desperation,'' she said Monday. ''We need your help.''

Connor Hagan, a spokesperson for the FBI, said that same day that the agency wasn't aware of ongoing communication between Guthrie's family and the suspected kidnappers.

Crime scene in a quiet neighborhood

Nancy Guthrie lived alone in the upscale Catalina Foothills neighborhood, where houses are spaced far apart and set back from the street by long driveways, gates and dense desert vegetation.