In this June 22, 2012, image taken from video, female airmen march during graduation at Lackland Air Force Base in San Antonio, Texas..
In this June 22, 2012, image taken from video, female airmen march during graduation at Lackland Air Force Base in San Antonio, Texas..
A U.S. Air Force instructor has been sentenced to 20 years in prison for raping and sexually assaulting several female trainees in a massive sex scandal at one of the country's largest military training bases.

A seven-member military jury at Lackland Air Force Base in San Antonio, Texas found Staff Sergeant Luis Walker guilty on Friday of rape, aggravated sexual contact and multiple counts of aggravated sexual assault.

Walker is among 12 Lackland instructors investigated for sexual misconduct toward at least 31 trainees.  Six instructors have been charged.