Seven years ago, Iowa farmer Todd Mullis was convicted of killing his wife, Amy, with a corn rake. Now, their 21-year-old son, Trysten, is speaking out for the first time. In an exclusive interview with 48 HOURS correspondent Erin Moriarty, Trysten says lawyers and investigators got it all wrong, and he's fighting to clear his father's name. Moriarty reports in "The Corn Rake Witness."
