The same sun scorched downtown Los Angeles that had seared the Iraq desert. Army Private First Class Samantha Cummings stood at attention holding a stack of boxes, her unwashed black hair slicked back in a ponytail and knotted military style. She stared out from Roberts Shoe Store onto Broadway, transfixed by a homeless man with hair and scraggly beard the color of ripe tomatoes. She’d only seen that hair color once before, on Staff Sergeant Daniel O’Conner. The man pushed …