The Pima County, Arizona, Sheriffs Department and the FBI are working to determine if a new possible ransom note in the Nancy Guthrie disappearance is credible.Sheriffs officials said the agency and the FBIs task force working o n the Guthrie investigation were recently made aware of the note and they are also aware of social media comments being made regarding this note.RELATED STORY | Flock founder says technology would have helped find Nancy GuthrieAccording to sheriffs officials, investigators are trying to determine the notes credibility.We do not have any additional information to provide at this time, officials stated.Guthrie, 84, the mother of NBC "Today" anchor Savannah Guthrie, was last seen at her home on the evening of Jan. 31. Guthrie disappeared after FBI investigators said she was kidnapped from her home in Pima County, Arizona. Footage from a doorbell camera showed a masked man with a gun tampering with a camera around the time of her disappearance.RELATED STORY | Union leader talks about missteps in Nancy Guthrie kidnappingHer disappearance has drawn national attention and sparked a months-long investigation involving the Pima County Sheriff's Department, the FBI and private forensic labs across the country. ...read more read less