In an emotional video posted to Instagram on late Wednesday afternoon, “Today” anchor Savannah Guthrie pleaded for her missing mother to come home.

“Momma, if you’re listening, we need you to come home, we miss you,” she said through tears.

“We need to know without a doubt that she’s alive and that you have her,” Guthrie said in response to reports of a potential ransom note. “We want to hear from you and we are ready to listen. Please reach out to us.”

The TV anchor’s video came on the fourth day of the desperate search for 84-year-old Nancy Guthrie.

Some of the most recent evidence in the investigation is also among the case’s most disturbing: purported ransom notes sent to media outlets.

Investigators have not yet confirmed whether the three similar notes are legitimate, but the sheriff of Arizona’s Pima County said Tuesday he was “absolutely not” dismissing them.

“When the note comes to us, it’s like any piece of evidence,” Sheriff Chris Nanos told CBS News. “You give it to us. You give us a lead. We’re going to look at every aspect of that lead and work it as a lead.”

Meanwhile, investigators are examining evidence that could speak to the timeline of the disappearance of Nancy Guthrie, who authorities believe was taken against her will from her Tucson-area home over the weekend. Her pacemaker last sent a signal to her iPhone around 2 a.m. on Sunday, according to a source briefed on the investigation. Her iPhone was left in the house.

Even as more information about the investigation is coming out, local law enforcement pushed back on claims that detectives have identified a suspect in the case.

The sheriff’s department asked the public Wednesday not to spread rumors about who may be responsible for the disappearance, saying they are speaking with “anyone who may have had contact with Mrs. Guthrie.”

“While we appreciate the public’s concern, the sharing of unverified accusations or false information is irresponsible and does not assist the investigation,” the department posted on X.

At least three different media outlets – TMZ and CNN Tucson affiliates KOLD and KGUN – report they received ransom notes earlier this week demanding millions of dollars in bitcoin for Nancy Guthrie’s safe return.

Those outlets say the notes also described specific evidence in Guthrie’s home, where authorities say she was last seen Saturday night. Nanos has declined to confirm whether those claims match the crime scene, but told CBS News investigators did share the note with Savannah Guthrie.

In response to a request for comment, the sheriff’s department referred CNN to a statement posted on X Tuesday.

“We are aware of reports circulating about possible ransom note(s) regarding the investigation into Nancy Guthrie,” the agency said. “We are taking all tips and leads very seriously. Anything that comes in, goes directly to our detectives who are coordinating with the FBI.”

Investigators are working to determine if the notes are authentic, the chief of detectives for the Pima County Attorney’s Office told Fox News.

“It may or may not be of value,” Fabian Pacheco said, “but it is still considered evidence. It is still considered a lead.”

Nanos has made it clear they do not believe Guthrie wandered from her home, saying she is “sharp as a tack” but has limited mobility and could not walk a long distance without assistance.

Investigators process evidence taken from Guthrie’s home

While the sheriff’s department has given few details about the investigation, more information is coming out about what was found at Nancy Guthrie’s one-story home, located in a secluded neighborhood framed by the famous saguaro cactus native to the Sonoran Desert that blankets Tucson.

Authorities found blood inside Guthrie’s home, the Los Angeles Times reported Tuesday, citing law enforcement sources not authorized to discuss the case publicly. The report did not detail whose blood was found or where in the house it was found.

There were signs of forced entry at the home, according to a person familiar with the investigation who spoke to The Associated Press.

Learning that Guthrie’s pacemaker stopped communicating with the phone early on Sunday morning, and that the phone was left in the home, could provide another clue on when she was taken.

Some modern pacemakers – devices that keep the heart in a regular rhythm – can transmit data to a phone app via Bluetooth so it can be shared directly with a patient’s doctor for easier monitoring. The connection generally would be possible only when the phone is near the pacemaker. Details about the model of Guthrie’s pacemaker weren’t immediately available.

Nancy Guthrie had dinner Saturday with family members who took her back to her home, where she lives alone, around 9:30 p.m., Nanos said.

Guthrie was uncharacteristically absent from church Sunday morning, prompting a friend to call relatives, who discovered she was not at home, authorities said.

The sheriff’s department collected DNA samples from the residence, Nanos said, but tests on those samples have not yet led them to any suspects.

Authorities are reviewing a report of a possible trespassing that occurred near Nancy Guthrie’s home on Jan. 4, as well as “all other cases within a close radius” to the residence, sheriff’s officials said in an update Wednesday.

Savannah Guthrie “has a security team” that has been staying in touch with the sheriff’s department, Nanos said. Nancy Guthrie’s home has been turned back over to Guthrie’s family.

Time is of the essence in the search for Guthrie because she takes medication daily that is critical for her health, and being without it “could be fatal,” Nanos said Monday.

Savannah Guthrie’s news colleagues ask for public’s help

The disappearance of her mother has understandably thrown Savannah Guthrie’s life into chaos. She rushed to Tucson to be with her family at a time she was originally supposed to be preparing to host NBC’s coverage of the Winter Olympics opening ceremony Friday from Milan, Italy.

The network confirmed Tuesday that Guthrie will no longer host the program and is focused on being with her family. NBC announced a new slate of Olympics hosts Wednesday and revealed Guthrie’s Today Show co-host, Craig Melvin, will also remain stateside.

NBC News programs throughout the week have repeatedly encouraged anyone who might have information about Nancy Guthrie’s disappearance to call the Pima County Sheriff’s Department tip line, 520-351-4900.

“Savannah has shared that it was her mother who taught her the power of prayer, the types of prayers that make you get on your knees and pray for God’s protection,” Tom Llamas said on “NBC Nightly News” Tuesday. “Savannah and her family need your prayers tonight. They also need your help.”

President Donald Trump called and spoke with Savannah Guthrie on Wednesday, according to a White House official.

Guthrie thanked the president for taking the time to call and told him her family is devastated and needs prayers, NBC later reported.

NBC reported Trump “assured the Guthrie family that every federal resource was available as needed.”

At an Oval Office event Tuesday, Trump expressed sympathy for Guthrie, saying he was open to committing more federal resources to the search.

“I always got along very good with Savannah,” Trump said. “Very unusual situation, but we’re going to find out.”