Air Force Staff Sgt. Luis Walker arrives July 20, 2012, for the fourth day of his trial at Lackland Air Force Base in San Antonio. Walker is accused of sexually assaulting 10 basic trainees, with charges ranging from rape and aggravated sexual assault to obstructing justice and violating rules of professional conduct. (Associated Press/San Antonio Express News)

Photo by: Billy Calzada

Air Force Staff Sgt. Luis Walker arrives July 20, 2012, for the fourth day of his trial at Lackland Air Force Base in San Antonio. Walker is accused of sexually assaulting 10 basic trainees, with charges ranging from rape and aggravated sexual assault to obstructing justice and violating rules of professional conduct. (Associated Press/San Antonio Express News)