Walter Jenkins' transcript from the Joint Services shows that he completed extensive military training courses while serving as a Gunnery Sergeant in the U.S. Marines. These included courses in basic military training, ammunition specialist training, leadership, nutrition, terrorism counteraction, and combat intelligence. Jenkins later took on roles as an Ammunition Noncommissioned Officer and Sergeant and completed additional advanced courses in areas like ammunition operations, staff noncommissioned officer leadership, and transportation of hazardous materials.