SAN ANTONIO -- Military officials say the initial flirtations that Staff Sgt. Luis Walker directed at the women he trained at a Texas Air Force base grew into something more sinister: threats and intimidation that eventually led to rape.
Walker's court-martial, resulting from a widening sex scandal at Lackland Air Force Base in San Antonio, began Monday with discussion of procedural issues in his case.
Opening statements had been expected by afternoon but debate among attorneys over various legal issues forced the military judge, Col. Wesley Moore, to delay them until Tuesday. Walker's father and two other family members were in the courtroom at the base.
Walker is among 12 instructors at Lackland who are being investigated in a scandal that has rocked one of the nation's busiest military training centers.
"We haven't had a case of this magnitude, certainly in recent memory," said Brent Boller, a spokesman for Joint Base San Antonio, which operates Lackland.
Walker faces the most serious charges in the case – 28 counts, including rape, aggravated sexual contact and multiple counts of aggravated sexual assault. He could get up to life in prison and a dishonorable discharge if convicted.
One of the legal issues debated Monday was whether to allow prosecutors to use in their opening statements a photograph Walker texted to one of his alleged victims. Walker appeared shirtless in the photo. Objections by defense attorneys over the photo's authenticity forced prosecutors to have the alleged victim briefly testify that the image had been sent to her by Walker.
"He sent a lot of photos," said the woman, whom The Associated Press is not naming because she is an alleged victim in the sex scandal. Prosecutors say Walker also told the woman that she was "hot" and "should have been naked."
Moore decided to allow prosecutors to use the photo of Walker.
The 10 female recruits Walker is accused of either sexually assaulting or engaging in inappropriate sexual conduct with are expected to testify during the court-martial. At least 31 female trainees have been identified as victims in the sex scandal.
Officials at Lackland are calling Walker's court-martial the "cornerstone case" in the ongoing investigation. A seven-member jury made up of military personnel will decide his case.
Walker's civilian attorney, Joseph Esparza, declined comment Monday.
A two-star general, Maj. Gen. Margaret H. Woodward, has launched a separate, independent investigation.
Advocates for female service members and members of Congress have started taking notice.
"It's a pretty big scandal the Air Force is having to deal with at this point," Greg Jacob, a former Marine infantry officer and policy director of the Service Women's Action Network, said last month. "It's pretty substantial in its scope."
The sexual misconduct at the base apparently began in 2009, but the first woman didn't come forward until last year. The first allegations were levied against Walker, who is accused of crimes that allegedly took place between October 2010 and January 2011.
According to the Air Force charge sheet, Walker had sexual intercourse with four of the 10 female recruits. He also is accused of making flirtatious or sexually suggestive comments, sending inappropriate text messages and sometimes groping his recruits.
The charge sheet also includes allegations that Walker forced five recruits to engage in sexual acts by threatening their military careers. He's accused of intimidating two of the women into lying about his alleged misconduct.
Walker was a trainer for about 18 months, until he was removed from his position in June 2011. He joined the Air Force in 2004 and previously was stationed at Dover Air Force Base in Delaware and at facilities in Montana and Korea. The Air Force is withholding his age and hometown.
Lackland is where every American airman reports for basic training – about 35,000 a year. About one in five is female, pushed through eight weeks of basic training by a flight of instructors that are about 90 percent male.
Six of the 12 instructors under investigation for misconduct face charges ranging from rape to adultery. Officials say nine of those instructors were in the same squadron.
The first court-martial in the case resulted in a plea agreement in June, when Staff Sgt. Peter Vega-Maldonado admitted to having sex with a female trainee. He struck a plea deal for 90 days of confinement. He later acknowledged being involved with a total of 10 trainees, a number previously unknown to investigators.