LE MARS, Iowa (AP) — An 82-year-old Iowa man has pleaded not guilty to killing his wife’s son during a domestic disturbance at his northwestern Iowa home in May. The Sioux City Journal reports that Thomas Knapp entered the plea Monday in Plymouth County District Court. Knapp is charged with first-degree murder and willful injury in the May 11 death of 51-year-old Kevin Juzek in Knapp’s Merrill home.

Police say Knapp shot Juzek with a 20-gauge shotgun through a bedroom door, then deliberately shot him again in the chest.