A friend of a 19-year-old Sioux City resident accused of stabbing to death his ex-girlfriend and another man testified that the defendant said he wanted to talk to the girl about their breakup and that he needed closure. The defendant, Tran Walker, has pleaded not guilty to two counts of first-degree murder. He's accused of killing 17-year-old Paiten Sullivan and 18-year-old Felipe Negron Jr. Police say Walker was in a car with the other two in January of last year when he stabbed Sullivan and