The F.B.I. and Pima County, Ariz., Sheriff’s Department in Tucson on Friday.Credit…Cassidy Araiza for The New York Times

Day 17: Where Things Stand

Family Cleared: Sheriff Chris Nanos of Pima County, Ariz., said in a statement on Monday that members of Nancy Guthrie’s family, including her three children, had been cleared of suspicion in her disappearance. “The family has been nothing but cooperative and gracious and are victims in this case,” he said.

A Timeline of Events: The case has confounded the authorities, who have given little insight into a possible motive. On Monday they pushed back on reports that it was being treated as a burglary gone wrong.

Hopes have soared with each apparent break, but Nancy Guthrie is still missing.Credit…Cassidy Araiza for The New York Times

Federal agents and sheriff’s deputies streamed into the quiet desert subdivision by night. They stepped past spiky agave plants and surrounded a house, preparing to serve a search warrant. A couple of miles away, investigators descended on a parked Range Rover and draped it with evidence tape.

For the second time in the excruciating weeks since Nancy Guthrie vanished, Friday’s burst of law enforcement activity in a southern Arizona neighborhood signaled a possible break in a case that has transfixed the country.

But, once again, the authorities later announced a disappointing result: Even after one person was questioned and the S.U.V. was towed away, no arrests had been made and there had been no trace of the 84-year-old Ms. Guthrie.

On Monday, there were few visible signs of significant progress in an investigation that for more than 16 days has frustrated the police and tormented Ms. Guthrie’s family — most visibly, her daughter, “Today” show host Savannah Guthrie, whose public pleas for help have reached millions around the world.

Indeed, as the search slogged into its third week, the most notable development was the exclusion of several people as possible suspects: Sheriff Chris Nanos of Pima County said Nancy Guthrie’s three children and their spouses were victims, and asked for an end to speculation about them. “The family has been nothing but cooperative and gracious,” he said.

His department has received tens of thousands of tips, combed the neighborhood by foot and by air and enlisted the help of the F.B.I. and other agencies. Still, the authorities have not identified a suspect and they do not know whether Ms. Guthrie is still alive.

The uncertainty has investigators scrambling. Until they find Ms. Guthrie, they must assume she is in imminent danger, which means they are moving faster than normal, said Lance Leising, a retired F.B.I. agent in Phoenix.

“When you do that, you run the risk of hitting dry holes, of swinging and missing,” said Mr. Leising, who also stressed that the public is aware of probably only “5 percent of what investigators know.”

The anticlimactic operation on Friday night echoed a chapter in the investigation that unfolded a few days earlier, when officers descended on Rio Rico, Ariz., about an hour’s drive south of Tucson. They detained one man and held him for hours while they questioned him. Sheriff Nanos thought his team had cracked the case.

But before long, investigators acknowledged they had hit a dead end. They released the man and continued their increasingly desperate search.

Ms. Guthrie was taken in the early hours of Feb. 1, the police have said. She had plans to watch a church service with friends later that morning, and when she did not show, they called her oldest daughter, Annie, who rushed to Ms. Guthrie’s home and found it empty. Blood, which tests would later confirm belonged to Ms. Guthrie, was splattered across the front stoop.

The authorities have released little information about what else they found at the house in the foothills north of Tucson, but Sheriff Nanos said it looked like a crime scene.

The details that have emerged have been ominous.

One day after Ms. Guthrie vanished, a Tucson-area television station received a ransom note purporting to be from her kidnapper. TMZ, the celebrity gossip outlet, received a similar note the next morning and reported that it demanded millions of dollars in Bitcoin for Ms. Guthrie’s return.

The F.B.I. advised the Guthrie family on how to proceed, and Ms. Guthrie’s three children released a statement telling the supposed kidnapper they were “ready to talk.” But the authorities have acknowledged the note may have been sent by an impostor. TMZ reported on Monday that it had received four such communications in all.

Perhaps the most tangible lead materialized on Feb. 10, when federal officials released photos and video recovered from Ms. Guthrie’s doorbell surveillance camera. The haunting images show a masked man approaching the door wearing gloves and a backpack, with what appears to be a handgun holstered at his waist.

The pictures opened up several new investigative avenues. Police officers sought to track down the source of the man’s clothing, which they said may have been purchased at Walmart. Then, on Feb. 12, sheriff’s deputies searching a field two miles from Ms. Guthrie’s home discovered discarded gloves that appeared to match the pair worn by the man in the surveillance video.

Preliminary testing revealed the gloves carried the DNA of an unknown man, and F.B.I. analysts were planning to enter the sample into a database. The process can take about 24 hours, officials said.

As they worked, the area around Ms. Guthrie’s house, once the site of steady activity, grew quiet. Online, armchair investigators puzzled over clues and speculated wildly. And Ms. Guthrie’s family projected hope.

“We still believe,” Savannah Guthrie said in a video posted to social media on Sunday evening
She did not mention a ransom, nor did she reference other details from the case.

Instead, she appealed directly to her mother’s captor: “It is never too late,” she said, “to do the right thing.”

DNA testing could produce results within days.

Image

The F.B.I. said the glove appeared similar to those worn by the masked man whose image was captured in surveillance footage from Nancy Guthrie’s doorbell camera.Credit…Cassidy Araiza for The New York Times

As the Nancy Guthrie abduction case stretches into a third week, investigators — and a public riveted by every mysterious development — have focused on DNA recovered from gloves found near her home.

The F.B.I. said that the gloves, collected last week in a field near the side of a road about two miles from her home near Tucson, Ariz., were sent to a private lab in Florida and that the DNA of an “unknown male” was found on them. That DNA profile will be loaded into the agency’s national database in hopes of identifying the man.

Peter Valentin, chair of the forensic science department at the University of New Haven, said on Monday that the laboratory analysis could produce results within days.

He said investigators would typically swab both the interior and exterior of the gloves to determine the identity of the user and if that person touched someone else — which could produce a second DNA profile.

“DNA is so easily transferred from one surface to another that the glove can tell us a bit of a story, not just give us information about who is wearing the glove,” said Dr. Valentin, a former major crimes detective with the Connecticut State Police.

Ms. Guthrie, the 84-year-old mother of Savannah Guthrie, co-host of the “Today” show, was taken from her home on Feb. 1.

The F.B.I. said the gloves appeared similar to those worn by the masked man whose image was captured in surveillance footage from Ms.
Guthrie’s doorbell camera. Released by the police last week, the footage shows a person wearing a ski mask, gloves and a backpack while standing at her front door on the morning of her disappearance.

Investigators collected about 16 other gloves near the home. Most of them belonged to searchers who discarded them in the vicinity.
A sheriff’s department spokeswoman said that investigators also discovered DNA on Ms. Guthrie’s property that was neither hers nor that of anyone in “close contact with her.” The police did not release details about where that DNA was found.