Investigators discovered that Graham had a criminal record for embezzlement by check forgery, and illegal transport of whiskey for which he had served 60 days in a Texas prison. They also determined that King's restaurant had been severely damaged by "a suspicious explosion" earlier that year, and that Graham had received the insurance settlement. Locals also suspected Graham of deliberately causing his new pick-up truck to be struck by a train that year, in order to collect the insurance. The FBI obtained use of a nearby barn where they re-assembled the fragments of the airplane collected from the site. They were able to determine that explosives were used, and that they had come from certain items of luggage in the baggage compartment. Based on that evidence as well as interviews, contradictory statements, physical evidence found at Graham's house, and finally a confession, Graham was arrested and charged with sabotage. The charge was later changed to murder.