GWEN IFILL: The U.S. military, under heavy fire in recent years over its handling of sexual assaults, released its latest report today on how it's managing the problem, drawing criticism from some.

Hari Sreenivasan has the story.

CHUCK HAGEL, Secretary of Defense: Good afternoon.

HARI SREENIVASAN: Defense Secretary Chuck Hagel laid out the new numbers at the Pentagon, based on a survey of the ranks by the RAND Corporation.

Estimated cases of sexual assault fell to about 19,000, down 25 percent from two years ago, but actual reports of assault increased 8 percent from last year. Hagel said the findings show both progress and the need for much more work.

CHUCK HAGEL: After last year's unprecedented 50 percent increase in reporting, the rate has continued to go up. That's actually good news. Two years ago, we estimated about one in 10 sexual assaults were being reported. Today, it's one in four.

These crimes, however, are still heavily under-reported, both nationally and in the military, so we must maintain our focus throughout the ranks and continue to earn the confidence of survivors.

HARI SREENIVASAN: Forty-three percent of the assaults reported by women and more than a third by men were penetrative sexual assaults. Those include rape and penetration with an object. The survey also found more than 60 percent of victims said they faced retaliation after they reported assaults.

But Missouri Senator Claire McCaskill, who sponsored a new law on military sexual assaults, suggested a different way of looking at that result.

SEN. CLAIRE MCCASKILL, (D) Missouri: I would be much more concerned about flat retaliation if we were getting numbers back saying, I don't have confidence in the command, the climate has not changed, we're not getting the support, and I wouldn't recommend other people coming forward.

But we got just the opposite numbers, high levels of satisfaction with command climate, high levels of satisfaction with their special victims counsels and their victim advocates.

HARI SREENIVASAN: The Pentagon report does call for additional enforcement procedures to prevent retaliation. It also recommends increasing unit leaders' knowledge and understanding of the issue.

But New York Senator Kirsten Gillibrand branded the study a failure of leadership. She's pushed to take sexual assault investigations outside the military chain of command.

SEN. KIRSTEN GILLIBRAND, (D) New York: What we have today is not zero tolerance. We have zero accountability. And if they continue to retain all decision-making in the hands of the smallest number of commanders, they're just — they're not recognizing the flaws in their own system. They're trying to cover it up. They're trying to shove it under the rug.

They're not seeking justice, and they're not protecting the men and women who are being raped. To have retaliation be unchanged, untouched is an egregious failure.

HARI SREENIVASAN: Gillibrand said she and other senators will try to amend the defense authorization bill this month, to make sexual assault investigations independent of commanders.