The Pima County Sheriff’s Department is sharing new details regarding Savannah Guthrie’s mother Nancy Guthrie’s final movements before her disappearance.

During a press conference held in conjunction with the FBI on Feb. 5, Sheriff Chris Nanos shared a visual timeline detailing the events that occurred between Nancy’s last sighting on Jan. 31 until she was reported missing on Feb. 1.

Titled “Nancy Guthrie Approx. Timeline,” the graphic first revealed that at 5:32 p.m. local time on Jan. 31, Nancy traveled to a “local family’s home.” In a prior interview with PEOPLE, Nanos confirmed that Nancy had dinner with her daughter Annie and Annie’s husband that night.

“Nancy travels to her local family’s home for dinner and playing games with the family, just visiting,” said Nanos during the Feb. 5 press conference as he explained the timeline. He also shared that Nancy traveled to the dinner via Uber.

“We did speak to a driver, because Nancy, we learned, had taken [an] Uber to the family residence, the daughter’s for dinner, and we located that driver and spoke with them and got that information,” he noted.

At 9:48 p.m., the family dropped Nancy off back at her home and the garage door was opened. Two minutes later, at 9:50 p.m., the garage door closed. This was the last time anyone reportedly saw Nancy.

“At 9:48 p.m., which is very consistent to what we were told by the family that Nancy was dropped off at home, and we know that because we have a garage door open at approximately — I can’t stress that enough — at approximately 9:48 p.m.,” said Nanos. “At 9:50 p.m. that garage door closes, because [at] that time we assume that Nancy’s home and probably going to bed.”

The next timestamp is from 1:47 a.m. on Feb. 1, when the timeline revealed that Nancy’s Ring doorbell camera disconnects. At 2:12 a.m., the software detects a person on camera, though Nanos confirmed during the press conference that there ultimately is no video available as there was “no subscription,” and “therefore [footage] would rewrite itself, cut up.”

“It just kind of loops right and covers up. That’s what our analysis teams have told us,” he continued. “We’re not done with that. We’ll do all we can, but that’s what it says: detects a person on camera. Could that be an animal? I imagine that’s possible. We don’t know that. We just have no video, but we’re not giving up on that.”

At 2:28 a.m., Nancy’s pacemaker app indicated a disconnect from her phone. Nearly 40 minutes passed between the time the Ring doorbell camera detected a person and the time Nancy’s pacemaker app indicated a disconnect.

On Feb. 1 at 11:56 a.m., the family checked on Nancy and “discovers her missing,” said Nanos. “At 12:03 p.m., 9-1-1 is called in to the Pima County Sheriff’s Department. I believe it’s about approximately 10 minutes later, 12 minutes later, our patrol teams arrive, they see the scene, and we start our response with our search and rescue teams and our detectives from Homicide and various units.”

According to the graphic, patrol arrived on scene at 12:15 p.m., and that is when the search for Nancy began.

At the press conference, Nanos — who previously said he believed Nancy was taken against her will, as she is “not in good physical health” and requires daily medication to survive despite being “of good, sound mind” — confirmed that the blood found on the exterior porch of Nancy’s Tucson home matches her DNA. This comes after the home was labeled a “crime scene” because of what authorities described as “very concerning” conditions found there.

Nanos also said that no suspects or persons of interest have been identified in Nancy’s apparent kidnapping. The alleged ransom notes that have been sent to several media outlets were also addressed at the conference.

FBI Special Agent in Charge Heith Janke said one individual has been arrested for “an imposter ransom demand” and investigators are looking into other notes, which were mentioned by the Today host and her siblings in a tearful plea video posted to Instagram on Wednesday, Feb. 4.

“We too have heard the reports about a ransom letter in the media,” Savannah said in the video. “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. We want to hear from you and we are ready to listen. Please, reach out to us.”

Janke revealed that the notes included a dollar amount and two deadlines — the first at 5 p.m. on Thursday, Feb. 5 and a second for Monday, Feb. 9, if the initial demand was not met. He added that one note referenced an Apple Watch and another mentioned a floodlight, but provided “no proof of life.”

“It’s clear the family wants to be contacted,” he said, later explaining that it’s unclear if the apparent abduction was targeted.

The FBI is now offering a $50,000 reward for any information leading to Nancy’s recovery or an arrest in the case.

Anyone with tips or leads is asked to call 1-800-CALL-FBI in addition to the Pima County Sheriff’s Department number, 520-351-4900.