A government investigation in 2005 concludes that a man was shot with a silenced pistol and his body dumped in the woods outside Paris in October 1979. However, a declassified diplomatic cable from a different government states that the same man left Paris alive on October 9 with a companion and traveled to Dhahran, Saudi Arabia via Zurich, Switzerland. Both documents are official government records. An analyst must determine which account is more likely accurate. What single category of records, if obtained, would most decisively resolve the contradiction between these two accounts?