Nancy Guthrie case could hinge on mystery tipster who emailed TMZ

A potential anonymous tipster in the Nancy Guthrie probe may be a female, even though she's been using male pseudonyms in her communications with the media, as experts believe human sources may be the best way to bring the unsolved case to a close. "The person used several different male names, but it was always the same Bitcoin address," TMZ founder Harvey Levin, who has received a series of emails from the purported whistleblower, told Fox News Digital Tuesday. "Other than being told they thin