THE HOUSE IS WATCHING. 🚨 The first day back was supposed to be about closure. But as Nancy Guthrie’s daughters stepped into the backyard, they encountered a “strange” anomaly that sent them running for the police. Someone had been there—and they left a signature that was intended only for the family to find. Amidst the overgrown grass and the silence of a house frozen in time, the discovery suggests that the secret to Nancy’s disappearance isn’t miles away in a mountain pass—it’s been under their feet this entire time. The investigation is moving back to where it all started

The desperate search for Nancy Guthrie continues as investigators scramble for clues into the 84-year-old’s mysterious disappearance

Nancy Guthrie’s Tucson, Ariz., house; Nancy and Savannah Guthrie.Credit : Joe Raedle/Getty; Don Arnold/WireImage

Nancy Guthrie’s home “has been processed and has been available” to her family since the first week she vanished, though authorities have returned to the house for further investigation, the Pima County Sheriff’s Office tells PEOPLE.

Other outlets reported on Wednesday, Feb. 25, that authorities are only preparing to turn the house over to the family at this time.

Nancy, the 84-year-old mother of Today show co-host Savannah Guthrie, is believed to have been abducted from her Tucson, Ariz., home in the early morning hours of Sunday, Feb. 1.

Her family called 911 at 12:03 p.m. local time on Feb. 1 to report her missing after she failed to join friends to watch a virtual church service.

Authorities descended upon Nancy’s longtime home to search for the mother of three, who was last seen going into her garage at 9:50 p.m. on Saturday, Jan. 31, after having dinner at her daughter Annie’s nearby home.

For days after Nancy vanished, investigators from the Pima County Sheriff’s Office and the FBI combed through evidence at her house, searching for any clue as to what happened to her.

During a Feb. 3 press conference, Pima County Sheriff Chris Nanos said that the house had been released to the family. On Feb. 8, the sheriff’s office said it will keep a security presence at the home for security concerns at the request of the Guthrie family.

The FBI and sheriff’s office needed to further investigate the property after Feb. 8, but the property was still available to the family at that time, a sheriff’s spokesperson tells PEOPLE.

“The family remains in possession of the home and will continue to do so,” says a law enforcement source familiar with the investigation.

One of the biggest breaks in the case came on Tuesday, Feb. 10, when authorities released surveillance photos and video footage of a masked man carrying a gun on Nancy’s front porch that same morning.

The FBI Phoenix office described the suspect as “a male, approximately 5’9” – 5’10” tall, with an average build. In the video, he is wearing a black, 25-liter ‘Ozark Trail Hiker Pack’ backpack” that may have been purchased at Walmart.

The identification of the backpack is one of the most promising leads authorities have had so far, said Pima County Sheriff Chris Nanos.

Authorities believe the assailant carried this type of backpack that may have been purchased at Walmart.FBI Phoenix/X

Nancy’s doorbell camera was disconnected at 1:47 a.m., local time. Then, a person was detected on the camera at 2:12 a.m. Sixteen minutes later, at 2:28 a.m., Nancy’s pacemaker was disconnected from the pacemaker app on her cellphone, authorities previously said.

Nancy Guthrie; Nancy Guthrie’s house in Tucson, Ariz.Savannah Guthrie/Instagram; Brandon Bell/Getty 

One promising lead came on Friday, Feb. 13, when the Pima County Sheriff’s Department (PSCD) said, “DNA other than Nancy Guthrie’s and those in close contact to her has been collected from the property.”

The DNA sample was mixed, Nanos said, however, making it difficult to identify whose it is.

Authorities also found a glove less than two miles from Nancy’s home that appeared to match gloves worn by the person pictured in previously released surveillance footage, according to the FBI, PEOPLE previously reported.

Investigators ran DNA found on the glove through the Combined DNA Index System (CODIS), the FBI’s national DNA database system, but failed to come up with any hits, the sheriff’s office said on Tues., Feb. 17.

Meanwhile, Nanos said in a statement on Monday, Feb. 16, that “The Guthrie family — to include all siblings and spouses — has been cleared as possible suspects.”

On Tuesday, Feb. 24, the Guthrie family announced a $1 million reward for any information leading to Nancy’s recovery or an arrest in the case. The FBI’s $100,000 reward for information remains active.