Wife Killer or Medically Insane?

After a woman is stabbed to death by her husband of three decades, shockwaves echo around a community. The prosecution claims this is a clear case of murder. For the defense, however, this is a one-in-a-million event. They argue that the husband was insane at the time of the killing. Will a jury believe that there is a medical explanation for this tragic event? Or will the husband spend the rest of his life behind bars?