The Air Force has dismissed its commander for basic training because of a sexual-assault scandal involving instructors and recruits, according to news reports from San Antonio, Texas.

Col. Glenn Palmer had been commander of the 737th Training Group for just over a year. All Air Force recruits train at Lackland Air Force Base, part of Joint Base San Antonio.

He assumed command just after Staff Sgt. Luis Walker, an instructor, was accused of raping one trainee and having sex or improper contact with several others, the Air Force Times writes. In late July, Walker was sentenced to 20 years and a dishonorable discharge for rape, aggravated sexual contact and multiple counts of aggravated sexual assault.

Palmer expanded the investigation into instructor-trainee relationships. Besides Walker, two other instructors have been convicted, four more are facing court-martial and eight others are under scrutiny, the Times says. At least 38 possible victims have been identified.

Col. Eric Axelbank, head of the 37th Training Wing and Palmer's superier, "lost confidence" in Palmer, the San Antonio Express-News reports, citing a spokeswoman.

Replacing Palmer was "part of Col. Axelbank's deliberate effort to fit the right leadership with the 737th Training Group in order to move forward," the spokeswoman said.

Having arrived just after Palmer last summer, Axelbank is leaving Lackland, for a job at the Pentagon, but the spokeswoman said he was not forced out because of the scandal.

An estimated 35,000 recruits train at Lackland every year, roughly 20% of them women. Of the 500 instructors, 90% are men.

The Express-News summarizes what steps Palmer and Axelbank took after they arrived at Lackland: