The search for Nancy Guthrie is in its 10th day. Here are the key developments

By Danya Gainor, CNN

The search for missing 84-year-old Nancy Guthrie, mother of Today show host Savannah Guthrie, has stretched into a second, anguished week, with mounting pressure on investigators and a family grappling with uncertainty.

Guthrie was last seen on 31 January, before she was apparently kidnapped, disappearing from her secluded home in Arizona's Catalina Foothills without her phone or critical medications.

The long days since she vanished have been marked by disturbing twists: purported ransom notes demanding millions of dollars, an intensive investigation, emotional video pleas from Guthrie's children publicly begging for the return of their mother and officials releasing video of an armed, masked person tampering with the doorbell camera at Guthrie's home.

Here is a timeline of key events in the case (all dates local time):

31 January

Nancy Guthrie joins her family for dinner and game night Saturday evening, Ubering to her older daughter Annie's nearby home around 5.32pm. Hours later, family members drop her back home. Guthrie's garage door opens at approximately 9.48pm and closes at 9.50pm.

"It is that time we assume that Nancy's home and probably going to bed," Pima County Sheriff Chris Nanos said at a news conference a few days after her disappearance.

February 1

Guthrie's doorbell camera is disconnected at 1.47am and about 25 minutes later, surveillance camera software detects movement. At 2.28am, data from Guthrie's pacemaker app shows the device was disconnected from her phone.

More than nine hours later, at 11.56am, the family realises she's missing when checking on her at home. A person close to the family told CNN Guthrie typically spends her Sundays watching virtual church services with friends at a nearby home. When she did not arrive Sunday morning, her friends alerted the Guthrie family.

Relatives call 911 at 12.03pm to report her missing, and Pima County Sheriff's Department patrols arrive by 12.15pm.

Investigators scour the scene, finding blood on the front porch which is later confirmed to be Guthrie's.

"There's still more items that have been submitted. We just haven't got them back yet," the sheriff would later say on 5 February "In the meantime, we're not just sitting on our haunches waiting. We do have a number of leads coming in."

3 February

On the third day of the search for Guthrie, several media outlets, including TMZ and CNN affiliates KGUN and KOLD, receive purported ransom letters demanding millions of dollars in bitcoin for her return. One note includes a first deadline of 5pm Thursday, 5 February, and a second deadline for Monday, 9 February.

4 February

In an emotional video posted to Instagram on Wednesday evening, Savannah Guthrie - flanked by her siblings Annie and Camron - pleads for her mother to come home four days after her disappearance. "We need to know without a doubt that she's alive and that you have her," Guthrie said in response to the reports of ransom notes. "We want to hear from you and we are ready to listen. Please reach out to us."

Law enforcement activity suddenly increases Wednesday early evening as detectives perform a "follow-up" at Guthrie's home, the sheriff's office says. Fresh crime scene tape wraps around the length of the house - and is taken down within a matter of hours.

5 February

Camron Guthrie issues another plea in a video posted on social media at 5pm local time as the first deadline given in the purported ransom note passes.

"Whoever is out there holding our mother, we want to hear from you," he says. "We haven't heard anything directly. We need you to reach out and we need a way to communicate with you so we can move forward."

The FBI, now jointly working the case with the Pima County Sheriff's Department, announces a USD$50,000 reward for information leading to the recovery of Guthrie "and or the arrest and conviction of anyone involved in her disappearance".

6 February

CNN affiliate KOLD receives a new purported ransom note on Day 6 of the search. The news station said it forwarded the message, along with the IP address from which the note originated, to law enforcement. The new note includes sensitive information but no deadline, according to an anchor at the news outlet.

Later that evening, gloved investigators are seen buzzing over Nancy Guthrie's property, placing evidence markers and climbing onto the flat, stark white roof of her home. Agents peer into bushes and scour the ground as a car which appeared to be Guthrie's is towed away.

7 February

On the one-week mark of Guthrie's disappearance, her three children say to her possible captor in a new social media video: "We will pay."

"We received your message, and we understand," Savannah Guthrie says in the new video. "We beg you now to return our mother to us so that we can celebrate with her. This is the only way we will have peace. This is very valuable to us, and we will pay."

Hours after the new video of the siblings, law enforcement officials are seen at Annie Guthrie's home. They leave shortly after 10.30pm with a bag and one deputy sheriff is seen wearing blue latex gloves.

8 February

Just before 11am, investigators return to Nancy Guthrie's home and are seen examining the septic tank near her property. Video shows investigators moving around a long stick in the tank, at times repeatedly jabbing it, and using a flashlight to peer inside.

"Detectives and agents continue to conduct follow-up at multiple locations," the Pima County Sheriff's Department said.

CNN affiliate KGUN, which received the first ransom note sent to some media stations, reports new details from the letter: The purported abductor demanded $6 million and threatened Guthrie's life if the 5pm Monday, 9 February, deadline isn't met.

9 February

Around 1.30pm, hours from the second deadline in the letter, Savannah Guthrie posts another video to social media, this time appealing to the public instead of her mom's alleged captor, asking for assistance.

"We are at an hour of desperation, and we need your help," the Today show host says, telling people to report anything "strange" to law enforcement.

The second deadline in the purported ransom note passes at 5pm.

10 February

The FBI releases new images and video from a camera at Nancy Guthrie's house, showing a person who appears to be armed, wearing a mask.

The images show "an armed individual appearing to have tampered with the camera at Nancy Guthrie's front door the morning of her disappearance," according to a post on FBI Director Kash Patel's X account.

"Over the last eight days, the FBI and Pima County Sheriff's Department have been working closely with our private sector partners to continue to recover any images or video footage from Nancy Guthrie's home that may have been lost, corrupted, or inaccessible due to a variety of factors - including the removal of recording devices. The video was recovered from residual data located in backend systems," Patel wrote in the post.

"Working with our partners - as of this morning, law enforcement has uncovered these previously inaccessible new images showing an armed individual appearing to have tampered with the camera at Nancy Guthrie's front door the morning of her disappearance," the post continued.

Shortly after the images were released, Savannah Guthrie posts them to her Instagram account.

"We believe she is still alive," Guthrie writes. "Bring her home."

- CNN