RIVERBANK — With a history of being a security guard with a license to carry a firearm and reported past boasting of phantom employment within the fire service, investigators have arrested Brandon Pettit, 25, in connection with the murder of his parents. The bodies of his mother and father were discovered after an Aug. 8 house fire in Modesto.The deaths of well-known Riverbank Karate for Kids business owner Scott Pettit and his wife Janet, both 59, were classified as homicides by Modesto Police investigators last week. On Saturday, Aug. 17, police announced the arrests of the Pettit’s son, Brandon Pettit and his friend, Felix Valverde, 26, of Oakdale on suspicion of murder, arson and conspiracy.Investigators are withholding the cause of death, but some witnesses in the neighborhood reported hearing gunshots from the residence on the evening of the fire.“I cannot believe that Brandon would be that stupid to kill the hand that feeds him,” said family friend and Riverbank business owner Daryl Daniel.