The disappearance of Nancy Guthrie, mother of the news anchor Savannah Guthrie, has reporters, neighbors and drones flooding streets and foothills in Tucson, Ariz.

A woman walks a dog past a desert driveway. Cactuses loom.
Nancy Guthrie’s home became a focus for the fascination of neighbors and the nation alike.Credit…Jan Sonnenmair/Getty Images

It began with the type of call the Pima County Sheriff’s Department fields every day: An 84-year-old woman gone from her home, a family in panic.

But when the deputies arrived at the low-slung brick house in a quiet desert neighborhood north of Tucson, Ariz., on Sunday, they quickly realized that this was no routine missing persons case.

There was the red splatter on the doorstep and damage, inside and out, that indicated an abduction. Then there was the identity of the lost woman, Nancy Guthrie, mother of “Today” show host Savannah Guthrie, one of the most-watched morning television anchors in America.

Before long, news of the investigation was everywhere. It flooded social media feeds and ricocheted around group chats. Reporters from across the country descended on Tucson, a city of about 500,000 that is home to the University of Arizona and 70 miles from the Mexican border. Citizen detectives bombarded the sheriff’s office with tips and theories, and President Trump on Wednesday called Savannah Guthrie with words of support.

As the search slogged through its fourth day, much remained murky. The few details that emerged seemed ripped from a Hollywood script or a history book. The possible kidnapping of a celebrity’s loved one — and the fixation that followed — conjured memories of the Lindbergh baby and Patty Hearst, crimes of a bygone era.

But Ms. Guthrie’s case has come with modern twists: Her abandoned cellphone and in-home security cameras, the drones that overflew the cactuses and palo verde trees of her subdivision hunting for clues. The supposed ransom note, first reported by the celebrity news site TMZ, demanding millions of dollars in Bitcoin. Local officials say they have a copy, and the F.B.I. is investigating.

Image

Savannah Guthrie and her mother before a crowd holding signs.

Savannah Guthrie, here with her mother in 2015, is one of the Arizona city’s most recognizable exports.Credit…Don Arnold/WireImage, via Getty Images

The intense interest the case has drawn has yielded many new leads, but it has complicated the investigation as well.

“This is really, for me, pretty new, all the media attention,” Chris Nanos, the Pima County sheriff, told a phalanx of reporters at a Wednesday news briefing. He said he was receiving so many media inquiries that it had become a distraction. “It’s just too tough, and it’s not fair to the case,” he added.

Later that day, in an interview with The New York Times, Sheriff Nanos said that the spotlight has made this case unlike any other he has handled, but he has told his deputies to concentrate on their urgent work.

“The reality is, it’s another crime,” he said. “We need to focus on the mission. We want to find Nancy, first and foremost. And we want to find her alive.”

Authorities have said every hour is crucial. If Ms. Guthrie does not take her daily medication, they warned, the consequences could be fatal.

The episode has shaken Tucson, where Ms. Guthrie moved with her family when her daughter Savannah was a baby. After her husband died in the 1980s, Ms. Guthrie raised her three teenagers there alone. Savannah Guthrie stayed close, attending college in Tucson and working there early in her career.

The star anchor is a hometown hero, one of the city’s most recognizable exports, who was poised to play a key role in NBC’s coverage of the Olympics, whose opening ceremony is Friday. Since Nancy Guthrie’s disappearance, her daughter has taken an absence from “Today,” and she has pulled out of the Winter Games. A church planned to hold a candlelight vigil for the family on Wednesday evening.

“She’s part of our community,” Sheriff Nanos said. “She hasn’t lived here for years, but boy, everybody watches that ‘Today’ show.”

One of those longtime viewers, Connie Cohn, had not known that she lived next door to Savannah’s sister and Ms. Guthrie’s older daughter, Annie Guthrie. On Wednesday, as police officers and journalists canvassed the street near her house in north Tucson, Ms. Cohn peered out her window and wondered what the commotion was about.

She called her husband, who took a guess: “Maybe it has to do with Savannah Guthrie’s mom,” he told her.

Image

Sheriff Chris Nanos, wearing a khaki and olive uniform, stands at a podium and gestures with his hands. Several reporters in front of him hold up their phones. On the left, an image of Nancy Guthrie appears on a screen.

Chris Nanos, the Pima County sheriff, said that the national spotlight has made this case unlike any other he has handled.Credit…Jan Sonnenmair/Getty Images

Ms. Cohn had been tracking developments in the search obsessively, refreshing news and social media. She grew up in Tucson, too, and followed Savannah Guthrie’s career.

“I feel like I know her,” she said.

She was saddened to learn that the home next door was one of the last places Ms. Guthrie had been seen.

On Saturday evening, Ms. Guthrie had dinner there with Annie Guthrie and her husband, Sheriff Nanos said. About 9:45 p.m., Ms. Guthrie’s son-in-law dropped her off at her home a few miles away and made sure she made it inside safely, the sheriff said.

When Ms. Guthrie did not show up for church Sunday morning, someone there contacted her family, who went to the house to check on her. Ms. Guthrie’s wallet, cellphone and car were still there, authorities said, but she was missing.

Police ruled out the idea that she might have mistakenly wandered outside and gotten lost: She has a medical condition that limits her mobility and “is of sound mind,” Sheriff Nanos said. When his deputies arrived, they saw “something at the home that didn’t sit well,” he added, and it became clear that she had been forced out against her will.

Authorities have been in close contact with relatives, who have all cooperated with the investigation, Sheriff Nanos said.

The sheriff said it was too soon to say whether the abduction was random or targeted, but he called the case extraordinary.

“We don’t see those kinds of monsters here,” he said.

On Ms. Guthrie’s block, an affluent area where the homes have large lots and views of the Catalina Mountains, neighbors have shared security camera footage with police and have even helped search for Ms. Guthrie in the foothills themselves. Police have not said whether the footage has turned up new evidence.

Image

Television reporters in a long row with lighting apparatus.

Reporters from across the country descended. Group chats exploded. Credit…Jan Sonnenmair/Getty Images

The scene on Tuesday blended the ominous and the everyday. After the police finished their work at Ms. Guthrie’s home, dried red liquid remained visible on the front doorstep. An Arizona Republic reporter watched an Amazon delivery driver drop off a package at the stoop. It was addressed to Ms. Guthrie.

Jorge Gomez, a recent retiree who has lived in the area for about 10 years, said the news was unnerving. “We are heartbroken,” he said. “I can’t believe what the family’s going through.”

Mr. Gomez’s own house has an alarm system and outdoor cameras, but since Ms. Guthrie was taken, he has been double-checking that they work every night. He has found himself on edge in a neighborhood that has always been tranquil.

That serenity is what drew many of his older neighbors to live there, including Ms. Guthrie. In a November “Today” segment, filmed in Tucson, she said the family decided to settle in the city in part because of its natural beauty.

“The air, the quality of life,” she said, smiling at her daughter. “It’s laid back and gentle.”

Lourdes Medrano contributed reporting from Tucson.