Air Force Staff Sgt. Brandon Ulmer, left, and Merl Mireles, an investigator with Orange County Sherriff's Department in California, prepare a controlled small blast firing device during the Raven's Challenge explosive ordnance disposal exercise at Camp Pendleton, Calif., Aug. 1, 2017. Raven's Challenge is an Army-funded exercise led by the Bureau of Alcohol, Tobacco, Firearms, and Explosives with support and participations from multiple federal, state and local agencies. DoD photo by EJ Hersom