Nancy Seaman, a suburban Detroit elementary school teacher, killed her husband, Bob, with a hatchet in May 2004. Nancy says she killed him in self-defense and that she had been abused for more than 30 years. At Nancy's murder trial, the couple's youngest son testified on behalf of his mother, while the other son says his mother was never abused and that she simply snapped. Contributor Maureen Maher reports.