U.S. Air Force Staff Sgt. Luis A. Walker arrives July 16, 2012, from a lunch break during his court martial at Lackland Air Force Base in San Antonio. Walker, a former training officer, is charged with illicit sexual contact with 10 female trainees. He is facing 28 counts including rape and is one of 12 instructors under investigation. (Associated Press/The San Antonio Express-News, Jerry Lara)

Photo by: Jerry Lara

U.S. Air Force Staff Sgt. Luis A. Walker arrives July 16, 2012, from a lunch break during his court martial at Lackland Air Force Base in San Antonio. Walker, a former training officer, is charged with illicit sexual contact with 10 female trainees. He is facing 28 counts including rape and is one of 12 instructors under investigation. (Associated Press/The San Antonio Express-News, Jerry Lara)