Air Force expands sex abuse investigation Rep. Jackie Speier (March 26, 2011 file photo). WASHINGTON, June 29 (UPI) -- The U.S. Air Force says it is expanding an investigation of a sexual misconduct scandal involving dozens of instructors at basic-training sites. The investigation began a year ago, with a woman filing a complaint at Lackland Air Force Base in Texas. It has grown into what observers say could become the worst sex scandal in the U.S. military since 12 male soldiers were charged with abusing female recruits and trainees at Aberdeen Proving Ground in 1996, The Washington Post reported Thursday. The Air Force investigation is focused on a unit of boot-camp instructors at Lackland, near San Antonio. About a fourth of the instructors in the 331st Training Squadron either were charged with crimes or are being investigated for sexual misconduct. One trainer was charged with raping or sexually assaulting 10 recruits. Senior Air Force officials said problems were found in other units, prompting them to open more investigations to determine how extensive harassment toward female recruits is and whether the Air Force's process for selecting male instructors is flawed, the Post said. "We are leaving no stone unturned," Gen. Edward A. Rice Jr., Air Force commander of training and education, said Thursday. I am being as aggressive as I can. Rice was in Washington to brief congressional members and Pentagon officials on the investigations. Last week, the Air Force relieved Lt. Col. Michael Paquette, commander of the 331st Training Squadron, citing "an unacceptable level of misconduct" by unit members. The Air Force appointed a two-star general to investigate whether the Lackland boot camp and other training sites have "systemic" sexual-misconduct issues, the Post said. About 3,200 incidents of sexual assault were reported or investigated by the armed services in 2011, Defense Department data indicated. In April, Defense Secretary Leon Panetta announced policies designed to encourage victims to come forward and to requiring that senior officers investigate all sexual assault complaints. Rep. Jackie Speier, D-Calif., has called on the House Armed Services Committee to conduct hearings as it did in the Aberdeen scandal, the Post said. "This scandal is exploding at Lackland, and it is frighteningly similar to what happened at Aberdeen," Speier told the Post.