While not in the field or completing his mission as platoon sergeant, Sgt. Ludwin Portillo, also known as DJ Boom, spends his free time performing and disk jockeying events. (U.S. Marine Corps photo by Cpl. Connor Hancock) - While not in the field or completing his mission as platoon sergeant, Sgt. Ludwin Portillo, also known as DJ Boom, spends his free time performing and disk jockeying events. (U.S. Marine Corps photo by Cpl. Connor Hancock)