An Oxford Junction man will spend 20 years in prison for killing his dad in 1998. Twenty-two-year-old Nathan Watson was sentenced Friday in Jones County Court in Anamosa. Watson struck a plea bargain to avoid spending life in prison and pled guilty to involuntary manslaughter. Watson killed his 42-year-old father aboard a converted school bus the two men were living in. Watson was ordered to pay a variety of court fines and attorneys fees, as well as 48-hundred dollars to cover the costs of his dad’s funeral.