Gunnery Sgt. Marlin Villacres checks his rear security. U.S. Marine Corps Gunnery Sgt. Marlin Villacres, platoon sergeant of 3rd Combat Engineer Battalion, 2nd Battalion, 7th Marine Regiment, checks his rear security during a patrol in Now Zad, Afghanistan, on Sept. 12, 2008. The Marine unit, which is a reinforced light infantry battalion, is clearing the city of improvised explosive devices. SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 472166-B-HBH02-103.jpg Photo Gallery