A Lawrence,Missouri man who encouraged his children to try and kill their mother by beating her with a baseball bat has been sentenced to 25 years in prison.Arthur Davis III was sentenced yesterday for attempted first-degree murder, aggravated kidnapping and contributing to a child's misconduct.Prosecutors say Arthur encouraged his 12-year-old daughter and 15-year-old son to kill his ex-wife last June 16. After the children began beating her, Arthur went to her house and helped with the attack and was heard on tape telling them to hit her harder. The woman managed to escape and ran down the street in only her underwear looking for help; she suffered several cuts to her head.Fueled by a heated child custody dispute, the attack occurred less than a week after the family learned a psychiatrist had recommended that the daughter continue living with her mother instead of with her father.The daughter was granted immunity for testifying against her father. The son entered a plea to a reduced charge of aggravated battery and was sentenced on Friday to three years in state custody. He will serve the sentence at a state youth center.