The FBI is continuing to investigate ransom notes related to the disappearance of Nancy Guthrie. Some of the notes have been deemed extortion attempts and have been discounted by the agency.

However, the FBI is still evaluating other ransom notes to determine their legitimacy. The total number of ransom notes received has not been specified by the agency.

For more information on the investigation, readers can refer to the original source, which may provide further details on the case and the FBI's ongoing efforts to evaluate the ransom notes.