Cpl. Chase Roesner, a chemical, biological, radiological and nuclear defense specialist with Combat Logistics Regiment 17, 1st Marine Logistics Group, pops a capsule of tear gas to train Marines aboard Camp Pendleton, Calif., Jan. 7, 2014. Marines received training on conducting reconnaissance and identifying potential CBRN threats, operating equipment designed to protect personnel from chemical threats and decontamination procedures to ensure Marines do not become casualties. (U.S. Marine Corps photo by Lance Cpl. Shaltiel Dominguez/ Released)