An anonymous writer terrorized the small town of Circleville, Ohio for almost 20 years by writing letters that exposed their alleged secrets. 48 Hours correspondent Erin Moriarty gave CBSN's Anne-Marie Green and Vladimir Duthiers a preview of "The Circleville Letters," which airs 10 p.m. ET, 9 p.m. CT on Wednesday, August 25 on CBS.
