Officials say they're investigating 'new message' regarding Nancy Guthrie

What we know

- Six days into the search for the mother of "TODAY" co-anchor Savannah Guthrie, no suspects or persons of interest have been identified, authorities said.

- Officials yesterday offered a timeline of the hours after Nancy Guthrie, 84, was dropped off by family at her home outside Tucson, Arizona, on Saturday night and when she was reported missing about noon Sunday.

- The FBI and Pima County Sheriff's Department this afternoon said it is aware of a "new message regarding Nancy Guthrie. It's not clear what kind of message it is and if it is connected to previously reported ransom notes.