Nancy Guthrie disappeared from her home in Arizona on February 1, with authorities suspecting that she was taken against her will

he reward for any information that leads to the arrest of Nancy Guthrie’s kidnapper has doubled thanks to an anonymous donation, with the donor adding $100,000 to the FBI’s existing $100,000 pool.

Nancy, who is the 84-year-old mother of Today show star Savannah Guthrie, has been missing for 18 days, and authorities are still searching for leads in the mysterious case.

The grandmother was first reported missing by her family on February 1 after she failed to show up for her usual church service, and investigators found blood on her doorstep upon arrival at the scene.

And now, CBS News reports that the FBI now has photos and names of people they believe may be the suspect seen on the surveillance video outside Nancy Guthrie’s front door.

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The reward for information has doubled thanks to an anonymous donation

Doorbell camera footage from outside Nancy’s home was then released by authorities, which showed a man dismantling the camera just before 2 a.m. on February 1. The individual wore a ski mask that covered his face, as well as black gloves, a large backpack and a holstered gun.

After expanding their search area around Nancy’s home, a black glove similar to that of the man in the camera footage was discovered and sent off for DNA testing. Unfortunately, no DNA matches were found in the Combined DNA Index System, leading to a dead end.

Pima County Sheriff Chris Nanos told reporters that his team was working closely with Google to retrieve additional footage from cameras around Nancy’s home, after investigators had gone door-to-door to ask neighbors for access to their surveillance footage.

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An individual was filmed dismantling Nancy’s doorbell camera on February 1

The team was also in contact with Walmart and several gun stores to find the origin of the individual’s backpack and gun holster. “That backpack, we could positively now identify as a backpack that is sold at one place only. That’s Walmart,” the sheriff said.

See the chilling doorbell camera footage below…

“So we’re working with our Walmart managers all across the state to try to find out how many sales there were of that backpack in the last 20, 30 days, the last 60 days.”

Authorities have also ruled out suspicions that Nancy had been taken across the border to Mexico, which is located 60 to 70 miles from her home. All of Nancy’s family members have been cleared of any suspicion, including her daughter, Annie Guthrie, and Annie’s husband, Tommaso Cioni, who were the last people to see her before her disappearance.

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The FBI discovered a black glove near Nancy’s home

Nancy had attended a games night with the pair before being dropped off at her home just before 10 p.m. on January 31.

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Nancy’s family were cleared of any suspicion

“To be clear…the Guthrie family – to include all siblings and spouses – has been cleared as possible suspects in this case. The family has been nothing but cooperative and gracious, and are victims in this case,” Sheriff Nanos said in a statement.

“To suggest otherwise is not only wrong, it is cruel. The Guthrie family are victims plain and simple.”