Lawyers for the western Iowa woman who was convicted in the shotgun slaying of her abusive husband have filed an appeal. In the 50-page appeal to the Iowa Supreme Court, lawyers for Dixie Shanahan-Duty of Defiance argue that Duty lost her self-defense argument because of mistakes made by her trial lawyer and the judge. In April, a Shelby County jury found Duty guilty of second-degree murder, and she received the mandatory sentence of 50 years in prison. Prosecutors are expected to file a brief supporting the conviction soon. The Supreme Court could make a decision in the case later this summer or fall.