A California man has pleaded guilty to harassing Nancy Guthrie's family by sending fake ransom notes related to her alleged abduction. Derrick Callella admitted to contacting the family seeking bitcoin transfers and information about the investigation. Meanwhile, the FBI continues to investigate other potential ransom demands in the ongoing disappearance case of the 84-year-old mother of Savannah Guthrie.

As Nancy Guthrie's missing person case unfolds, ransom notes indicate a complicated narrative surrounding her disappearance and presumed death.

Last month, Guthrie’s daughter and NBC anchor Savannah Guthrie delivered an emotional plea to viewers seeking information about her disappearance.