Here are the key developments in the weekslong search for Nancy Guthrie

Tucson, Arizona (CNN) — The search for 84-year-old Nancy Guthrie, mother of “Today” show host Savannah Guthrie, has stretched into a fourth, anguished week, with mounting pressure on investigators and a family grappling with uncertainty.

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

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

The latest on where things stand

• Guthrie family offers a million dollars reward: After nearly a week of silence, Savannah Guthrie posted an emotional new video on social media saying the family will offer up to $1 million for information leading to her mother’s recovery.

• No leading theory: Authorities say they believe Nancy Guthrie was removed from the home against her will. But investigators still have no leading theory about a motive, according to a source. They have not ruled out the possibility more than one person may have been involved, the sheriff said Friday.

• Doorbell footage from two dates: The masked person seen on the doorbell camera footage of Nancy Guthrie’s Arizona home the morning she is believed to have been kidnapped was also recorded at her doorstep on another night, a source told CNN. FBI Director Kash Patel’s release of the image believed to be from a different night surprised local and federal investigators on the ground as they hoped to keep the detail confidential, another source said.

• DNA analysis: Investigators continue to run lab analysis on DNA found at Nancy Guthrie’s house, Pima County Sheriff Chris Nanos said Thursday. DNA on gloves found 2 miles from the home did not return any matches in the national database known as CODIS, and doesn’t match DNA found the house, either, Nanos said.

• Other evidence: Officials determine the man seen in doorbell video was carrying an Ozark backpack, the sheriff said, but are still trying to identify other items and where they might have been purchased. Teams of FBI and local law enforcement investigators are also reviewing “thousands of hours” of video obtained from the greater Tucson area, a law enforcement official familiar with the case told CNN.

• Family not suspects: Nancy Guthrie’s adult children and their spouses are not suspects in her February 1 disappearance, the sheriff says, calling any suggestion otherwise “cruel.”

• Tip lines: If you have information that could help investigators, you can call 1-800-CALL-FBI or 520-351-4900. You can also submit information at tips.fbi.gov.

Timeline of key events

Wednesday, February 25

Several people who appear to be investigators were seen walking around Nancy Guthrie’s property Wednesday morning— the most activity CNN has seen at the residence in days. It’s unclear who they’re affiliated with or what prompted the action.

The Pima County Sheriff’s Department told CNN its investigators weren’t at Guthrie’s home this morning. CNN has reached out to the FBI Phoenix office for information.

Tuesday, February 24

Twenty-four days since her mother disappeared, Savannah Guthrie acknowledged Nancy “may already be gone.” In an emotional video, the “Today” host said her family is “blowing on the embers of hope” and still believes their mother will come home. But, she acknowledged a difficult truth.

“She may already be gone,” Guthrie said. “She may have already gone home to the Lord that she loves … If that is what is to be, then we will accept it. But we need to know where she is.”

The family is offering a personal reward of up to $1 million for any information leading to Nancy’s recovery, Guthrie said. This action was taken after careful consultation and in coordination with law enforcement a source close to the family told CNN.

“Somebody knows. We are begging you to please come forward now,” she said.

She also acknowledged her family is not alone in suffering through the “uncertainty” of a missing loved one. So, she said, they are also donating $500,000 to the National Center for Missing and Exploited Children.

“We are hoping that the attention that has been given to our mom and our family will extend to all the families like ours who are in need and need prayers and need support,” Guthrie said.

The family’s reward is in addition to the FBI’s $100,000 reward for information about Guthrie, the agency said Tuesday. The announcement raises the total reward to up to $1.2 million for information on Guthrie’s disappearance.

The Guthries have continued to “stay in lockstep” with investigators, a source close to the family told CNN. The reward comes after investigative updates have appeared to slow as the search enters its fourth week.

In other developments, the FBI will be shifting its investigative command post from Tucson to Phoenix, FBI Phoenix Public Information Officer Kevin Smith told CNN Tuesday, while emphasizing that everyone who is working on the ground with the sheriff’s department will stay and it is not a reduction in resources.

Monday, February 23

The masked person seen on the doorbell camera footage of Guthrie’s home the morning she is believed to have been kidnapped was also at her doorstep on another night, a source tells CNN.

The photos and video of the masked person on Guthrie’s doorstep — released by the FBI on February 10 — were taken on two different days, rather than just on February 1, when authorities believe she was abducted, the source says. That’s because the masked suspect is not wearing a backpack in one of them, according to the source.

ABC News first reported the suspect appears to have been at her door before February 1.

The Pima County Sheriff’s Department said in a statement “there is no date or time stamp associated with these images” and “any suggestion that the photographs were taken on different days is purely speculative.” It added the investigation is ongoing and “conclusions will be guided by verifiable evidence and established facts.” CNN reached out to the FBI Phoenix office for comment.

The photos and video show a masked, armed suspect approach the door and tamper with the doorbell camera the morning of her disappearance. The suspect is described as male, approximately 5’9” – 5’10” tall and having an average build, according to the FBI.

Local and federal investigators on the ground in Arizona searching for Nancy Guthrie were surprised by video and photos posted on social media earlier this month by the head of the FBI depicting her suspected abductor, another law enforcement source involved in the investigation told CNN.

FBI Director Kash Patel posted on February 10 chilling video of a man at Guthrie’s front door before her disappearance, including a follow-up post announcing and releasing “additional recovered images from the same camera at Nancy Guthrie’s front door the morning of her disappearance.”

But investigators in Tucson believed one of the images Patel posted — showing the man without a backpack or gun — was not actually from the date of her abduction, but possibly from weeks before as the man appeared to surveil her home, the source said.

Authorities had hoped to keep specific details of that image confidential while they worked to identify the suspect and a motive, the source said. Local investigators were also puzzled by the fact FBI headquarters insisted the new imagery would be tweeted from Patel’s own X account rather the general FBI account.

“It would have been nice to know what (FBI) headquarters was planning to release,” the source said.

The FBI has not responded to CNN’s request for clarity on Patel’s social media post.

Residents in Guthrie’s neighborhood were previously asked by the sheriff’s department to submit video as far back as January 1, but the request specifically focused on two dates. Authorities also requested footage that includes cars, traffic, people or pedestrians, or anything that feels out of the ordinary or important.

Saturday, February 21

Detectives and agents are back in Nancy Guthrie’s neighborhood on Saturday, canvassing the area as part of their investigation, according to the Pima County Sheriff’s Department. “No additional details will be provided,” the agency said.

Thursday, February 19

Mexican officials say there is currently no indication Guthrie was brought into Mexico.

“The FBI informed us that they currently have no leads to suggest that this woman could be in Mexico,” said Carlos Flores, General Commissioner of the Criminal Investigation Agency for the State of Sonora, speaking to reporters Thursday.

Sonora officials say there’s been no specific request for assistance in the investigation from the FBI.

Wednesday, February 18

Authorities have canvassed residences, businesses and government agencies for surveillance video to identify any possible indication of where Guthrie may have been taken, a law enforcement official familiar with the case says. Reviewing the “thousands of hours” of footage is a painstaking process and often involves slowing down video frame by frame to look for anything of interest, the source adds.

Officials on both sides of the US-Mexico border were also told to be on the lookout for clues that might assist in the case as part of standard investigative procedures, according to a law enforcement official familiar. Investigators briefed US Border Patrol agents and Mexican law enforcement authorities, the official says.

Due to the proximity of Tucson to the border, the official says, both US and Mexican border officials are aware of doorbell camera footage showing a suspect possibly responsible for Nancy Guthrie’s disappearance.

It is not uncommon for US authorities to brief their Mexican counterparts out of an abundance of caution about cases involving fugitives who may abscond from the United States.

Madres Buscadoras de Sonora (Searching Mothers of Sonora) — a Mexican nonprofit organization of women activists comprised of volunteers, mothers and wives — tells CNN it was contacted by a member of the Guthrie family to help with the search. The group’s founder, Ceci Flores Armenta, says some women plan to meet with the family Thursday and possibly start looking for Nancy Guthrie on both sides of the border.

Meanwhile, Nanos told CNN affiliate KOLD decisions on how to pursue leads in the search are being made jointly by command center leadership, which includes chiefs from his department, FBI leadership and federal and local prosecutors, among others.

88-Crime, the Pima County and Tucson affiliate of the national Crime Stoppers organization, offered a reward of up to $102,500 for information leading to an arrest in the case. Up to $100,000 of that is from a private donor, it says.

This is separate from the FBI’s offer of up to a $100,000 reward, and will only be available for information reported directly to 88-Crime, it says. Tipsters can remain anonymous.

Earlier, the “Today” set is filled with yellow flowers, mirroring the growing tribute outside Nancy Guthrie’s home, where neighbors, friends and strangers from across the country have sent or delivered bouquets of support for the Guthrie family.

Tuesday, February 17

The Pima County sheriff announces Tuesday afternoon that DNA tested from gloves found near Nancy Guthrie’s house does not have any matches in the national database known as CODIS, and doesn’t match DNA found at her home, either.

DNA found at her Tucson property is still being analyzed, Nanos says, adding that nothing in the investigation has any matches in CODIS. CODIS is the FBI-managed Combined DNA Index System, a national database that holds more than 19 million offender profiles, according to the agency.

Investigators are looking into other genetic genealogy options to check for matches with the DNA evidence, the sheriff says, noting CODIS is just one of the databases available.

Meanwhile, investigators have been visiting gun shops in the Tucson area. The suspect was seen in doorbell video with a gun and a holster that the sheriff said “had some pretty unique characteristics.”

CNN spoke to roughly a half dozen shop owners, most of whom said they weren’t able to comment on what investigators asked them. But one owner said FBI officials visited about a week ago and showed him pictures of various people, although he didn’t recognize any of the individuals.

Another gun shop owner told CNN affiliate KOLD that an FBI agent asked him to review between 18 to 24 images and names for gun purchases. He also said he searched the shop’s computer system and found no matches, KOLD reported.

Investigators continue to follow up on various leads, including processing evidence from the homes of two people who were detained and later released, Nanos says in an interview with CNN affiliate KNXV. The sheriff assures that “if detectives weren’t satisfied, they wouldn’t have been released.”

Monday, February 16

The sheriff’s department clears all Guthrie family members – including siblings and spouses – as possible suspects in Guthrie’s disappearance in a Monday afternoon statement.

Nanos’ statement puts an end to online speculation throughout the weekslong search for Nancy Guthrie about her family’s possible involvement.

“The family has been nothing but cooperative and gracious and are victims in this case,” Nanos says in the statement posted on X. “To suggest otherwise is not only wrong, it is cruel.”

Sunday, February 15

A glove found near Nancy Guthrie’s home appears to match those worn by the suspect captured in doorbell camera footage outside her house the morning she disappeared, the FBI says in a statement.

The glove, containing DNA, is one of “approximately” 16 that investigators found near Nancy Guthrie’s home, most of which the FBI says belonged to searchers who discarded them while working in the area.

Meanwhile, in a video posted to Instagram, Savannah Guthrie shares a new message to the possible kidnappers of her mother.

“It’s never too late and you’re not lost or alone, and it is never too late to do the right thing,” Savannah Guthrie says.

The “Today” show anchor says she and her family are still hopeful. “We still have hope and we still believe,” she says.

Friday, February 13

As neighbors tie yellow ribbons around trees in Nancy Guthrie’s neighborhood in solidarity and hope for her safe return, a local official tells CNN investigators have received more than 30,000 tips from the public so far.

Later Friday, authorities conduct an operation at a residence roughly 2 miles from Nancy Guthrie’s home, the sheriff’s department says.

No arrests are made, though one man is questioned and released, with law enforcement believing him not to be the kidnapper, a law enforcement official tells CNN. More than a dozen vehicles, including those from SWAT and forensics, are seen at the location.

Local authorities and the FBI are also at a second location near where law enforcement activity is underway.

Authorities are seen at the site investigating a gray Range Rover in a parking lot of a restaurant.

Thursday, February 12

As the search for Nancy Guthrie enters its 12th day, the Pima County Sheriff’s Department asks neighbors to submit video footage that includes cars, traffic, people or pedestrians — and anything they feel may be out of the ordinary or important for law enforcement to review.

Later in the day, the FBI releases a description of the person seen in footage captured by Nancy Guthrie’s doorbell camera, and the agency raises the reward for information to $100,000.

The suspect is described as male, approximately 5’9” – 5’10” tall and having an average build. The backpack he was wearing in the video is identified as a black, 25-liter “Ozark Trail Hiker Pack.”

Savannah Guthrie also shares a touching tribute to her mother on social media.

The video features a short clip of a young Savannah Guthrie and her sister, Annie Guthrie, smiling at the camera while handing their mother flowers, as well as a photo of the three siblings and their mother.

“We will never give up on her,” Savannah Guthrie captions the post.

Wednesday, February 11

Thousands of tips for investigators to pore over are generated after the February 10 release of surveillance photos.

TMZ reports the media outlet received a “bizarre letter” from someone purporting to know Nancy Guthrie’s kidnapper.

Harvey Levin, the outlet’s founder, tells Fox News the person who sent the email demanded a single bitcoin in exchange for information about the kidnapper.

CNN has not been able to independently verify the existence or authenticity of the note.

Meanwhile, CNN speaks to Carlos, the man detained February 10 by law enforcement, outside his home in Rio Rico, Arizona. He says investigators told his family he’d been stopped as a result of an anonymous tip that came after surveillance photos of the suspect were released Tuesday.

Tuesday, February 10

The FBI releases new images and video from a camera at Nancy Guthrie’s house, showing a person 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.

Shortly after the images and videos are released, Savannah Guthrie shares them to her social media accounts.

“Someone out there recognizes this person,” she writes. “We believe she is still out there. Bring her home.”

Later Tuesday, the Pima County Sheriff’s Department announces it has detained a person for questioning in the case after pulling them over “during a traffic stop” in Rio Rico, around 60 miles south of Tucson, near the US-Mexico border. Hours later Wednesday morning, the person is released.

A spokesperson with the Pima County Sheriff’s Department also tells CNN a search warrant is being executed at a home in Rio Rico in connection with the case.

Separately, Patel says the agency is looking at “persons of interest” in the case without saying who might be under suspicion.

Monday, February 9

Days after several media outlets received purported ransom letters demanding millions in bitcoin for Nancy Guthrie’s return, a second deadline mentioned in one of the notes passes Monday at 5 p.m.

Hours before the deadline, around 1:30 p.m., 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.

Sunday, February 8

Just before 11 a.m. Sunday, investigators are seen examining the septic tank near Nancy Guthrie’s property after police were notably absent from her home Saturday. Video shows investigators moving around a long stick in the tank, at times repeatedly jabbing it, and using a flashlight to peer inside.

Meanwhile, CNN affiliate KGUN, which received one of the ransom notes sent to some media stations, reports new details from the letter: The purported abductor demanded $6 million and threatened Nancy Guthrie’s life if the 5 p.m. Monday, February 9, deadline isn’t met.

Saturday, February 7

On the one-week mark of Nancy 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 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 the home of Annie Guthrie. They leave shortly after 10:30 p.m. with a bag and one deputy sheriff is seen wearing blue latex gloves.

Friday, February 6

CNN affiliate KOLD receives a second purported ransom note on Day 6 of the search. The news station says 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 in the 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 that appeared to be Nancy Guthrie’s is towed away.

Thursday, February 5

Camron Guthrie, Savannah Guthrie’s brother, issues another plea in a video posted on social media at 5 p.m. 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 $50,000 reward for information leading to the recovery of Nancy Guthrie “and or the arrest and conviction of anyone involved in her disappearance.”

Wednesday, February 4

In their first emotional video posted to Instagram, Savannah Guthrie – flanked by Annie Guthrie and Camron Guthrie – pleads for her mother to come home on Wednesday evening, four days after her disappearance.

“We need to know without a doubt that she’s alive and that you have her,” Savannah Guthrie says 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 Nancy Guthrie’s home, the sheriff’s department says. Fresh crime scene tape wraps around the length of the house — and is taken down within a matter of hours.

Tuesday, February 3

On the third day of the search for Nancy Guthrie, several media outlets, including TMZ and CNN affiliates KGUN and KOLD, receive the first purported ransom letters demanding millions of dollars in bitcoin for her return.

One note includes a first deadline of 5 p.m. Thursday, February 5, and a second deadline for Monday, February 9.

Sunday, February 1

Hours after Nancy Guthrie was reportedly home from dinner with family, her home doorbell camera is disconnected at 1:47 a.m., and about 25 minutes later, surveillance camera software detects movement. At 2:28 a.m., data from Nancy Guthrie’s pacemaker app shows the device is disconnected from her phone.

More than nine hours later, at 11:56 a.m., the family realizes she’s missing when checking on her at home.

A person close to the family later tells CNN Nancy Guthrie typically spends her Sundays watching virtual church services with friends at a nearby home. When she did not arrive Sunday morning, her friends alert the Guthrie family.

Relatives call 911 at 12:03 p.m. to report her missing, and Pima County Sheriff’s Department patrols arrive by 12:15 p.m.

Investigators scour the scene, finding blood on the front porch that is later confirmed to be Nancy 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 February 5. “In the meantime, we’re not just sitting on our haunches waiting. We do have a number ofleads coming in.”

Saturday, January 31

Nancy Guthrie joins her family for dinner and game night Saturday evening, Ubering to her older daughter Annie Guthrie’s nearby home around 5:32 p.m. Hours later, her son-in-law, Tommaso Cioni, drives her home. Nancy Guthrie’s garage door opens at approximately 9:48 p.m. and closes at 9:50 p.m.

“It is that time we assume that Nancy’s home and probably going to bed,” Nanos would say at a news conference a few days after her disappearance.