A Dickinson County man convicted of severely injuring his son by shaking the infant will now go on trial for murder, as the boy died after being in a coma for months. The trial of Korey Klaasen of Spirit Lake is set to begin tomorrow in Sibley. Klaasen was convicted of child endangerment and sentenced to up to 10 years in prison for injuring his son, Kyler, in 1998. Kyler was in a coma for over a year and died in August, 1999. Prosecutors then decided to charge Klaasen with first degree murder. Lawyers who worked both sides of the Shelby Duis case will be in the court room. The prosecutors who brought charges against Shelby’s mother, Heidi Watkins, and Watkin’s boyfriend for the death of the Spirit Lake toddler will argue the state’s case. Klaasen is defended by the attorneys who represented Watkins.