LACKLAND AIR FORCE BASE, Texas - Shock. Anger. Disgust. Disbelief.
Those are some of the emotions roiling this sprawling base in San Antonio in the wake of the biggest U.S. military sex scandal in years. Investigators are looking into allegations of sexual assault by at least a dozen training instructors, six of whom have been charged.
So far, 31 women have come forward with claims ranging from inappropriate Facebook posts to dorm room rapes, and 35 instructors have been removed from their posts pending investigations.
More than 70 members of Congress have signed a letter calling for a House hearing on the allegations, and the Air Force has dispatched a two-star general to lead an inquiry in addition to the criminal investigations.
"There has never been a case like this before on this base," says Collen McGee, a spokeswoman with the 37th Training Wing, tasked with training recruits.
Instructors at Lackland train every airman joining the Air Force. More than 35,000 recruits each year go through 8½ weeks of basic training here.
They are trained by nearly 500 instructors. The instructors - known in other military branches as drill sergeants or drill instructors - are 89% male.
One of those instructors, Staff Sgt. Luis Walker of the 326th Training Squadron, is at the center of the scandal. His court- martial began Monday and has included emotional testimony by female trainees under his watch who allege he lured them into stairwells or his office and forced them into sexual encounters.
On Wednesday a woman who alleges she was one of Walker's victims broke down on the stand minutes after an intense cross-examination where the instructor's attorney pointed out inconsistencies in her statements made to Air Force investigators.
"It took me a very, very long time to get that out of my memory. Why would I want to talk about that? Would you?" the witness said, sobbing.
She was identified as Victim 7 in court. USA TODAY typically does not identify alleged victims of sexual abuse.
Base officials have described Walker's case as the "cornerstone" of an ongoing investigation.
Walker is charged with 28 criminal counts, including rape, aggravated sexual contact and aggravated sexual assault, involving 10 women, according to his Air Force charge sheet. He faces a dishonorable discharge and life in prison if he is found guilty.
Another instructor, Staff Sgt. Peter Vega-Maldonado, admitted last month to having sex with a female trainee and agreed to 90 days confinement as part of a plea deal.
In her testimony Wednesday, the woman said Walker told her to meet him in an empty dorm and to bring a towel.
"And when I walked in, he pulled me into him after he closed the door. He grabbed me by the arm and pulled me into him and started kissing me," she said.
She was silent as Walker began to undress her, she said. "I just let it happen to me," she said.
However, Walker attorney Maj. Naomi Dennis challenged the woman's testimony, saying it had "evolved over time." The woman responded, "Do you understand how embarrassing that is?" and broke down on the witness stand moments later.
As allegations began to surface last year, base commanders implemented a slew of policy changes, including installing 40 new comment boxes in stairwells that allow trainees to anonymously voice mistreatment allegations. The changes include incorporating more sexual misconduct discussion into the training course, McGee says.
Commanders also took the unprecedented step in March of shutting down basic training for a day to survey all 6,000 trainees on how they were being treated. Investigators are interviewing trainees who have gone through the course the past two years, looking for improprieties, McGee says.
"We're looking at everything," she says. "We're not just looking at what happened. We're looking at how it happened."
Still, the widening sex scandal has weighed on the morale of instructors, the majority of whom are outstanding airmen, says Master Sgt. Greg Pendleton, 37, head of the base's Military Training Instructor School.
"It's taxing. It's disheartening," he says. "You can see it in the look of individuals."
Sgt. Chrissie Slifer, 36, has trained more than 1,400 recruits during six years on base. She says she's never seen or heard of inappropriate sexual contact between recruits and instructors.
If that line is ever crossed, instructors would be the first to report fellow instructors, she says.
"We don't want someone like that as part of us," Slifer says.
Her biggest concern is that the public's perception of Lackland is tarnished due to the alleged incidents.
"It's hurtful," she says. "There are a lot of us here for the right reasons."
But military sexual assaults will continue until their investigations are taken out of the hands of base commanders and given to independent military prosecutors, says Anu Bhagwati, executive director of the Service Women's Action Network, a New York-based advocacy group for military women.
Military women and men are less likely to report sex crimes if their bosses decide how far the investigation should go, Bhagwati says. The Defense Department estimates that around 19,000 sexual assault cases occur throughout the U.S. military each year but only 3,200 - or 17% - are reported, according to statistics from the Pentagon's Sexual Assault Prevention and Response Office.
Repercussions from the Lackland case - both in emotional damage to assaulted trainees and potential policy changes down the road - will be felt for years to come, Bhagwati says.
"The impact is enormous," she says. "What happens in Lackland affects the entire Air Force. The residue of this scandal will linger for quite some time."
U.S. Rep. Jackie Speier, D-Calif., called on the head of the House Armed Services Committee last month to convene a hearing on the Lackland scandal. She has yet to hear a reply, despite garnering the signatures of 77 colleagues who support a hearing.
Military sexual assaults will continue until Congress changes how those crimes are handled, she says.
"This issue repeats itself," Speier says. "We have got to stop an environment where men and women enlisted in the military have a greater likelihood of being assaulted by someone in their unit than by an outside enemy."