jack Ball was driving at police station with bill Grayden in the backseat . Christopher Whitmore pulled up beside car , shooting his son and then wife . he had history of domestic violence but motivation for killing not guilty .
Melissa Ball was parked at gas station with son Grayden in the backseat . Christopher Whitmore pulled up beside car , shooting his son and then wife . Couple had history of domestic issues but motivation for killing not known .