A 13-year-old boy was arrested Monday in Gypsum, Colorado, after being accused of shooting his father in the head twice and killing him. He allegedly concealed the murder for days, telling his father's co-workers that he was out sick. Police say the mother was not living with the family. When authorities responded to a tip from the employer, the boy answered the door and said his father was dead. There is no known motive for the killing.