CBS News looks at the decades-old mystery
                                
                                
                                    (Newser) -
                                    The weirdness began in Circleville, Ohio, in 1977. And, spoiler alert, though  CBS News' 48 Hours  digs way deep into the decades-old mystery, it remains one with plenty of theories and no certainty. In March of that year, anonymous letters started appearing in mailboxes accusing residents of everything from embezzlement...