The television news anchor Savannah Guthrie said in an emotional video on Wednesday night that she and her siblings were ready to listen to ransom offers from whoever might have abducted their mother, but that the family would first need proof that she remains alive.
In the video, Ms. Guthrie, an anchor on the “Today” show, tried to hold back tears as she sat between her older siblings, Annie and Camron, and read from a piece of paper. She said that her family had heard about purported ransom letters that had been sent to news outlets seeking money in exchange for the release of their mother, Nancy.
“We are ready to talk,” Ms. Guthrie said in the video. “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.”
The plea for proof of life was a dramatic turn in the mystery of what happened to Nancy Guthrie, 84, after her son-in-law dropped her off at her home in a quiet neighborhood just outside of Tucson, Ariz., on Saturday night. She did not show up for church the next morning, prompting a large-scale search that has grown only more desperate.
The Guthries and police officials have said that Nancy Guthrie is mentally sharp but has trouble moving around and requires daily medication.
“She needs it to survive,” Savannah Guthrie said in the video. “She needs it not to suffer.”
Chris Nanos, the sheriff in Pima County, Ariz., has said that investigators have no suspects and do not know how many people might have been involved in the kidnapping or what their motivations might be. The sheriff’s department is expected to hold another news conference on Thursday at 11 a.m. Mountain time.
President Trump spoke with Ms. Guthrie by phone earlier Wednesday, and he said on social media after her video was posted that he had directed all federal law enforcement to be at her and the local police’s disposal.
“The prayers of our Nation are with her and her family,” Mr. Trump wrote. “GOD BLESS AND PROTECT NANCY!”
Nancy Guthrie’s older daughter, Annie, said in the video on Wednesday night that the three siblings were “normal human people” who need their mother.
“Mama, Mama, if you’re listening, we need you to come home,” she said. “We miss you.”
Sheriff Nanos said that Nancy Guthrie had been having dinner with Annie and Annie’s husband, Tommaso Cioni, who live nearby in Tucson, on the night she disappeared. Mr. Cioni had made sure she made it safely inside before he left, the sheriff said.
When deputies arrived the following day at Nancy’s home, they saw something “that didn’t sit well,” Sheriff Nanos said in an interview. He declined to elaborate, but said there was concerning evidence beyond a red splatter that journalists had observed on the front doorstep.
“There were things at the home that we recognized as problematic,” he said. “Inside, outside, all over.”
The authorities have begun to receive results of forensic tests from DNA gathered at the scene, he said, but they have not yielded leads. “So far, nothing has come back to say, ‘Ah ha, this is your guy,'” Sheriff Nanos said.
At least two news outlets, TMZ, the celebrity news website, and KOLD, a CBS affiliate in Tucson, said they had received messages that appeared to be ransom notes and had forwarded them to the authorities.
TMZ said the note that its newsroom received had demanded millions of dollars in Bitcoin and included a description of damage to Nancy Guthrie’s house that presumably occurred during her abduction. It was unclear whether the description of the damage was accurate.
The sheriff’s department has said it is aware of the notes, has copies of them and is taking all leads seriously. The F.B.I. has been conducting interviews and reviewing cellphone data.
Nancy Guthrie, a retired communications professional, has been a stalwart volunteer and was often seen around her Tucson community. She lives in a quiet, wealthy part of the Catalina Foothills, just north of Tucson, but not in a gated community — rather, homes are separated by large lots, cactuses and desert scrub.
At a vigil on Wednesday evening inside a church just down the road from Ms. Guthrie’s house, scores of residents lit candles and prayed for her safe return.
Laura Gargano, who lives behind her, said she has seen neighbors installing security systems in the days since the disappearance.
Ms. Gargano said she met Ms. Guthrie a few times and visited her at her house about a year ago. On Wednesday evening, she lit a candle for her neighbor and stood in the back of the chapel.
“I hope her family is able to find moments of peace and hope,” Ms. Gargano said. “I hope they get some comfort from knowing that so many people are thinking of them and caring about their family.”
Karen Henckel, who lives on a cul-de-sac that winds up to the back of Ms. Guthrie’s home, said earlier in the day that the neighborhood is a friendly place where people generally don’t have to think twice about whether they locked their doors.
She said she had not noticed anything strange in the neighborhood before Ms. Guthrie’s disappearance and hadn’t heard anything unusual on the night of the apparent abduction.
Nancy Stanley, a longtime family friend, said neighbors felt helpless about the search. Ms. Stanley worked with Savannah Guthrie for several years at a local television station, KVOA, and knows her and her mother to be people of faith.
Now, she said, “the family’s in this limbo, this horrible hell.”
Susan C. Beachy contributed research.
Nicholas Bogel-Burroughs reports for The Times on national stories across the United States with a focus on criminal justice.
