On the very day they returned home, Nancy Guthrie’s two daughters reported a deeply disturbing discovery in the backyard

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.