NORTH PLATTE, Neb. (AP) – An attorney for a North Platte man accused of killing his wife is appealing a judge’s earlier ruling that the man is competent to stand trial. North Platte television station KNOP reports that attorney Stephen Potter thinks his client, 34-year-old Roger Diaz, needs another mental evaluation. Diaz did not speak Monday during his arraignment on a second-degree murder charge. Potter gave notice that he intends to submit an insanity defense. Police say Diaz killed 35-year-old Michelle Diaz in their backyard around 2 a.m. on June 25. An ambulance crew found her unresponsive, and she died at a local hospital. Police say Roger Diaz told officers his wife fell from the backyard steps, but later changed his story. Diaz is being held on $2 million bail.