The black nitrile glove that briefly electrified the search for Nancy Guthrie is a dead end.

Pima County Sheriff Chris Nanos announced Tuesday that DNA recovered from the glove, found two miles from the 84-year-old's Tucson home, matched neither the DNA found inside her property nor any profile in the FBI's CODIS criminal database.

Three weeks after Guthrie vanished from her home in the Catalina Foothills, investigators have burned through leads at a staggering pace and have precious little to show for it. The FBI has fielded more than 13,000 tips. The Pima County Sheriff's Department has taken over 18,000 calls, generating between 40,000 and 50,000 leads, the Daily Mail reported. And yet the mother of Today Show star Savannah Guthrie remains missing.

A trail of evidence that leads nowhere

Nancy Guthrie was last seen on the evening of January 31, entering her home. Hours later, in the early morning of February 1, her pacemaker disconnected from an Apple Watch at the residence. A masked suspect appeared on her doorbell camera just before her disappearance.

Since then, the investigation has produced a series of dramatic moments that collapsed almost as quickly as they materialized:

• A delivery driver, Carlos Palazuelos, was arrested in connection with the case one week before Tuesday's announcement, then released without charge hours later. He angrily denied any involvement.
• Pima County SWAT officers raided a home two miles from Nancy's on Friday. No one was detained.
• FBI agents stopped a Range Rover Sport and questioned its driver around the same time. He was released without charge.
• Sixteen gloves were found scattered around the home, most of which belonged to investigators combing the scene.

The glove discovered Sunday, two miles away, seemed like it might finally break through the noise. It didn't.

The DNA question that actually matters

DNA expert CeCe Moore, appearing on NBC's Today, had already tempered expectations before the results came in. She suggested the glove's distance from the home made it an unlikely match:

"In my opinion, it's not. It's really too far from the crime scene."

But Moore raised a far more pointed question, one that cuts closer to the heart of where this investigation stands:

"My biggest question is, have they found DNA from an unknown male inside that house?"

That question hangs over everything. The Pima County Sheriff's Department disclosed Tuesday that investigators obtained additional DNA evidence from inside Nancy's home, evidence that is still being analyzed. Whether that evidence belongs to someone who shouldn't have been there remains the central unknown.

Scrutiny of Sheriff Nanos

Sheriff Nanos has come under scrutiny for his handling of the case, with allegations that crucial errors were made in the first hours of the search. The specifics of those alleged missteps remain unclear, but the pattern is familiar: in high-profile cases, the first hours are everything, and if those hours are squandered, every subsequent lead starts at a deficit.

Authorities have publicly cleared Nancy Guthrie's family members as possible suspects, including her son-in-law, Tommaso Cioni, who had been the subject of unfounded online speculation. Whatever happened to Nancy Guthrie, the people closest to her aren't responsible.

A daughter's plea

On Sunday night, before the glove results were announced, Savannah Guthrie posted a video to Instagram speaking directly to whoever may be holding her mother:

"It is never too late to do the right thing."

"And we are here. And we believe in the essential goodness of every human being, that it's never too late."

Those are the words of someone running out of answers but not out of hope. They're also the words of someone who understands, perhaps better than most, that public attention is a resource with a shelf life.

What three weeks without answers tell us

The sheer volume of tips and leads, tens of thousands of them, reveals both the power and the limitation of public engagement in a case like this. Every American with a television knows Nancy Guthrie's name. But volume is not the same as clarity, and attention is not the same as progress.

A masked figure on a doorbell camera. A pacemaker that went silent in the middle of the night. An 84-year-old woman who walked into her home and never walked out. These facts have not changed since the first days of February. What has changed is the growing sense that the investigation is chasing possibilities rather than narrowing them.

The additional DNA evidence still awaiting analysis may yet turn the case. It may be the thread that unravels the whole thing. But three weeks in, with a glove that led nowhere, a SWAT raid that produced nothing, and an arrest that didn't stick, the people of Tucson and a daughter in New York are still waiting for the one lead that holds.