Nancy Guthrie: FBI offers $50,000 reward for information on disappearance

PHOENIX - As the search for Nancy Guthrie continues in the Tucson area, FBI officials say they are also stepping in to help with the information.

What we know:

During a news conference on Feb. 5, an official with the agency said a $50,000 reward is being offered for "information leading to the recovery of Nancy Guthrie, and/or the arrest and conviction of anyone involved in her disappearance."

"The FBI has agents, analysts, and professional staff employees, working day and night without partners at the [Pima County] Sheriff's Department," Heith Janke with the FBI said.

In addition, FBI officials say they have made an arrest in connection with an "imposter demand".

The backstory:

Nancy, who is the mother of "Today" show host Savannah Guthrie, was last seen on the night of Jan. 31 after being dropped off at her Catalina Foothills home near East Skyline Drive and North Campbell Avenue. She was reported missing the next day after her family was notified that she hadn't shown up for church.

Authorities say Nancy is without her necessary medication. On Feb. 5, authorities gave the following timeline for the case:

Jan. 31

• 5:32 p.m.: Nancy travels to her family's home
• 9:48 p.m.: Family drops Nancy off at home and garage door opens
• 9:50 p.m.: Garage door closes

Feb. 1

• 1:47 a.m.: Doorbell camera disconnects
• 2:12 a.m.: Software detects person on camera (no video available)
• 2:28 a.m.: Pacemaker app shows disconnect from phone
• 12:03 p.m.: 911 call to PCSD
• 12:15 p.m.: Officers arrive at Nancy's home

Read More: Nancy Guthrie disappearance: Day 5 latest updates

Dig deeper:

Authorities believe Nancy was taken from her home against her will. An email sent to Tucson television station KOLD reportedly included a deadline and a demand for a specific amount of money for Nancy's safe return. The station turned the email over to the PCSD, which is working with the FBI to determine the note’s credibility.

Along with her siblings, Savannah released an emotional video plea on Wednesday night, calling for the safe return of their mother.

"We too have heard the reports about a ransom letter in the media," Savannah said. "As a family, we are doing everything that we can. We are ready to talk. However, we live in a world where voices and images are easily manipulated. We need to know without a doubt that she is alive and that you have her."