A former South Carolina police officer who authorities say kidnapped and held his estranged wife and infant son hostage in Georgia says he intends to enter an insanity plea.An attorney for David Dietz says in court documents filed this week he intends to introduce evidence that his client was suffering from a mental disease or defect at the time of his alleged crimes.Dietz has pleaded not guilty to several federal charges in South Carolina, including kidnapping and carjacking.