It been a week since Nancy Guthrie was last seen. She joined family for dinner before returning home at night, not to be heard from since.

Investigators are still trying to make sense of what happened to the mother of Today show host Savannah Guthrie.

Here’s what we know, six days into the investigation into her disappearance.

Who is Nancy Guthrie?

The 84-year-old mother and grandmother lives alone in the Catalina Foothills community, just north of Tucson, Ariz.

She has three children: Annie, Camron and Savannah, the youngest. Nancy Guthrie’s husband, Charles, died in 1988.

Pima County Sheriff Chris Nanos, whose department is leading the investigation, said that officials do not believe Guthrie simply wandered away from her home, but that she was taken by force.

“Nancy Guthrie is of great, sound mind. This is not a dementia-related” case, Nanos said. “She is as sharp as a tack.”

Guthrie does, however, suffer other health problems, including relying on a pacemaker and requiring a medication that if missed, could be fatal.

Guthrie’s children described her as in fragile physical health.

What is the timeline of her disappearance?

On Saturday evening, last week, Guthrie took an Uber to one of her daughters’ homes to have dinner and play games, according to a timeline of events presented by the sheriff’s department.

At around 9:48 p.m., a family member dropped Guthrie back off at home for the night. Several hours later, at 1:47 a.m., Guthrie’s doorbell camera disconnected.

About a half hour after that, the camera detected movement, but officials said they were unable to retrieve the footage. Minutes later, at 2:28 a.m., Guthrie’s pacemaker disconnected from its app.

On Sunday afternoon, when Guthrie did not show up to church as expected, fellow parishioners alerted her family and the police were called.

Authorities say that a securitay camera is missing from the front of Guthrie’s home and that DNA testing had confirmed that blood splatter found on the front porch belonged to Guthrie.

Five days into their search, officials said they were still hopeful Guthrie could be brought home alive.

“We still believe Nancy is still out there. We want her home,” Nanos said at a Thursday press conference.

Do police have a suspect?

No, police have said that they have not yet identified a suspect or person of interest in the case.

On Thursday, the FBI announced a reward of $50,000 for any information leading to Guthrie’s recovery and the capture and conviction of whomever might have taken her.

Officials said that they were aware of ransom notes, including one that had been sent to a handful of media outlets earlier in the week.

FBI special agent in charge of the bureau’s Phoenix office, Heith Janke, said that the FBI is taking that note seriously.

The note made mention of particular details, including an Apple Watch and a floodlight at Guthrie’s house. The note’s author also included two deadlines — one that expired Thursday at 5 p.m. and another scheduled for Monday. Authorities have not said whether the note included specific demands or consequences for not meeting the deadlines.

Officials declined to reveal further details of the letter.

On Friday evening, the Pima County Sheriff’s Department said in a statement on social media that they were aware of “a new message” and were “actively inspecting” the information provided to verify its authenticity.

Officials determined that at least one ransom demand is fraudulent and have arrested a person in connection with the message.

“To those imposters who are trying to take advantage and profit from this situation, we will investigate and ensure you are held accountable for your actions,” Janke said.

Has the family spoken out?

Savannah Guthrie and her siblings have on social media made direct appeals to the alleged abductor, asking for an open line of communication and proof that their mother is still alive.

“Whoever is out there holding our mother, we want to hear from you,” Camron Guthrie, Nancy’s son, said in a Thursday video posted to Savannah’s Instagram account. “We need you to reach out, and we need a way to communicate with you so we can move forward.”

On Saturday evening, Savannah said in a video posted on her social media that the family was willing to pay a ransom for the return of their mother.

“We received your message and we understand,” she said in the video, joined by her siblings.

“We beg you now to return our mother to us so that we can celebrate with her,” she said. “This is the only way we will have peace. This is very valuable to us and we will pay.”

It’s unclear whether the family has made contact with their mother or an alleged abductor.

The family previously posted a video asking kidnappers for proof of life.

“We are ready to talk,” she said, reading from a statement. “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.”

What are the next steps?

Officials say that they are working tirelessly to ensure Guthrie’s safe return home.

President Trump said on social media this week that he had spoken to Savannah Guthrie to offer his support, including having directed federal law enforcement to be at the family’s “complete disposal, IMMEDIATELY.”

Law enforcement have urged anybody with any details on Guthrie’s disappearance to come forward.

NPR’s Chandelis Duster contributed to this report.