Nancy Guthrie ransom notes contain repeated writing quirks that could help identify suspect, expert says

A pair of messages that may have been sent by someone with knowledge of Nancy Guthrie's suspected kidnapping from her Arizona home contain a series of clues about their author, according to retired Colorado investigator Lisa Miller, who said grammatical habits and sentence patterns suggest both notes were likely written by the same person — and could ultimately trigger the tip detectives have been waiting for.

Guthrie is the 84-year-old mother of "Today" co-host Savannah Guthrie. Authorities...