U.S. Air Force Staff Sergeant Luis Walker was sentenced on Saturday to 20 years in prison for the rape and sexual assaults of recruits at Lackland Air Force base in San Antonio, Texas.
The drill instructor had been found guilty by a military jury on Friday of 28 charges, including rape and aggravated sexual assault.
Ten accusers testified against him in court during the five-day court martial.
Walker displayed no emotion when the military jury of six men and one woman returned the verdict after about seven hours of deliberation.
Walker had faced a maximum penalty of life in prison and a dishonorable discharge from the Air Force as a result of his conviction on the charges, which included rape, aggravated sexual contact and multiple counts of aggravated sexual assault.
During the five-day trial, prosecutors called all 10 accusers to testify, including one who appeared by video hookup because she just had a baby.
They told similar stories of being befriended by Walker, who offered to provide guidance on how to survive the Air Force's rigorous 8-1/2-week-long basic training program at Lackland.
But the friendly advice quickly turned to hugs, kisses, sexual text messages and harassment, the victims said. Four of them testified that Walker used threats, intimidation and his authority as a drill instructor to coerce them into engaging in sex.
"He used them and then moved on," lead prosecutor Major Patricia Gruen told the jury.
Defense lawyers questioned why prosecutors never presented any forensic evidence, including photographs or DNA, to corroborate the victims' testimony.
Brent Boller, a spokesman for Joint Base San Antonio, which operates Lackland, was in the room with nine of the 10 victims when the verdict came down. "You could discern that they were quite emotional," Boller said.
Walker is the first of seven instructors at Lackland referred for court-martial. Five others are formally under investigation, and 35 more instructors have been taken off active duty while officials look into accusations.
It is the largest sex scandal to hit the U.S. military since the 1990s, when accusations of sexual misconduct at the Army's Ordnance Center and School in Aberdeen, Maryland, rocked the Pentagon.
So far, the Lackland case has triggered two Air Force investigations as well as calls for a congressional probe.
It has also highlighted the explosive issues of sexual harassment and gender discrimination in the U.S. Armed Forces and rekindled a wider debate over how best to train women and integrate them fully into all branches of the military.
© 2015 Thomson/Reuters. All rights reserved.