There are serious problems in the way the Department of Defense is handling sexual assaults, according to a preliminary report (PDF) by the Government Accountability Office.

The GAO released the report last Thursday to coincide with a congressional hearing on sexual assault in the military. At the hearing, Rep. Henry Waxman (D-CA) threatened to issue subpoenas to a range of Pentagon officials who had prevented a key witness from testifying.

The report is based on interviews and surveys with more than 3,900 servicemembers at 14 locations both in the U.S. and abroad. Of those, 103 people said they had been sexually assaulted in the year leading up to the survey, but just over half of them said that they hadn't reported it. The GAO cited another report (PDF), by the Pentagon’s own internal statistics department, that says upwards of three quarters of sexual assault victims in the military do not report the abuse.

The underreporting links to another problem highlighted in the report: Many soldiers and other personnel don’t understand how to make reports of sexual assault, even if they want to.

Since 2004, the Army has implemented training sessions for new procedures introduced after Congress directed the Pentagon to create a comprehensive policy to prevent sexual assault.

The new policy includes an option to make anonymous reports so that victims can obtain counseling and medical help without being required to identify who assaulted them. That track, called a "restricted report," does not result in criminal investigations.

But the training doesn't seem to be working, according to research cited by the GAO, which found that at some bases, as many as 43 percent of people who had taken the training didn't understand how to report an assault.

While the GAO found that most commanders -- who are responsible for putting the training in place -- are supportive of the new measures, commanders on at least three bases had resisted posting materials advertising the new procedures.

The report is the first indication of how well the Pentagon's efforts to tackle sexual assault are working. The Pentagon itself has not set up any criteria to measure its own progress or to oversee the commanders responsible for implementing the program -- another point of criticism.

The report noted, however, that the program is relatively new and that the Army's main focus has been on getting it started, not on monitoring.

The Army representative at Thursday's hearing, Lt. Gen. Michael D. Rochelle, did not respond directly to the GAO's claims about inadequate training and the unwillingness of commanders to implement the policy. But, he wrote in his opening statement, the Army is taking measures to improve the system.

"Recently, the Chief of Staff sent a message to commanders that he and the Secretary are not satisfied with the result of our prevention program, that we will overhaul our sexual assault prevention program, and aggressively take steps to develop a sound prevention initiative," he wrote. We've also contacted the Pentagon and we'll post their response when we get it.

Other witnesses at the congressional hearing included Rep. Jane Harman (D-CA) who said there is an epidemic of sexual abuse in the military, and described (PDF) visits to a VA Health Center in Los Angeles where doctors told her that 29 percent of the female veterans they see say they were raped during their military service.

The final GAO report is due later this month.