A Dixon man is in jail on murder charges after authorities say the pickup truck he was driving under the influence struck a motorcycle head-on and killed its two passengers Sunday. 43-yr-old Christopher Duncan of Dixon was charged with the deaths of 24-yr-old Johnathan Gray of Utica and 26-yr-old Paula M. Hamilton of Livermore. Webster County Coroner Larry Vanover pronounced both Gray and Hamilton dead on the scene. Neither were wearing helmets.