The sheriff investigating the kidnapping of Nancy Guthrie, mother of US TV presenter Savannah Guthrie, says authorities believe they have a motive, but have not identified a suspect.
Pima County Sheriff Chris Nanos told NBC News that "we believe we know why he did this". He said authorities "believe it was targeted", but they were "not 100% sure of that".
Guthrie, 84, has been missing since she was taken from her home in Tucson, Arizona, on 1 February.
A nationwide search has unveiled certain clues, including DNA evidence and ransom notes, but no suspect has been identified.
Nanos declined to elaborate on the suspected motive, as he said it could compromise the integrity of the ongoing investigation to do so.
