WASHINGTON — Reports of sexual assaults in the military increased by an unprecedented 46 percent during the last fiscal year, the Pentagon said Thursday.
It wasn’t possible to know whether the spike represented an increase in assaults, an increase in the percentage of reports, or both. Defense Department officials portrayed the sharp increase as a sign that people are more confident about coming forward now that improvements are being made to the military’s system for handling assaults.
There were 3,553 sexual assault complaints from October 2012 through June, compared to 2,434 reports during the same period the previous year, according to statistics presented Thursday at the start of a two-day public meeting of an independent panel looking into the issue.
The report to the so-called Response Systems Panel said an increase in reports was registered across all service branches — Army, Navy, Air Force, and Marines. And it noted that, while statistics for the full fiscal year are not yet available, there were more reports of sexual assault in the first three quarters of fiscal year 2013 than the 3,374 reported during the entire 2012 budget year.
‘‘A change in reports of sexual assault may reflect a change in victim confidence in Department of Defense response systems,’’ said a slide presentation prepared for the panel.
The department in recent years has started a number of programs aimed at boosting the confidence of victims, including holding awareness training across the forces and adding legal help and more social services for those reporting assaults.
Despite official data reported annually on sexual assaults, the Pentagon acknowledges that the actual number of assaults could be several times higher and that many assaults go uncounted because of reluctance in the military, as in the civilian sector, to report such crimes.
The new data and Thursday’s public meeting comes just weeks before the Senate is expected to take up a proposal to change how the military justice system deals with sexual assaults. The proposed legislation would remove commanders from the process of deciding whether serious crimes, including sexual misconduct cases, go to trial, and it would give that authority to seasoned trial lawyers who have prosecutorial experience and hold the rank of colonel or higher.
The chief advocate of the change, Senator Kirsten Gillibrand, a New York Democrat, is expected to push to attach her measure as an amendment to the annual defense policy bill that the Senate is expected to consider the week of Nov. 18.
On Wednesday, Gillibrand was joined at an emotional news conference by a victim of assault, retired military members, victims’ advocates, and a bipartisan group of senators who back her legislation. Forty-six senators support the proposal, including 38 Democrats and eight Republicans.
But her idea is opposed by the Pentagon and the chairman of the Armed Services Committee, Senator Carl Levin, Democrat of Michigan, as well as by Senator Claire McCaskill, Democrat of Missouri.
Levin agrees with the Joint Chiefs of Staff that commanders should remain involved in deciding whether to prosecute sexual assault cases. Military leaders have argued that removing the decision from their purview would undercut the ability of officers to maintain good order and discipline in their units.
Earlier this year, the Armed Services Committee backed a bill designed to reform the military system by requiring a review of commander decisions not to prosecute sexual assault cases. The proposal also would have made it a crime to retaliate against victims who report a sexual assault and also called on the Pentagon to relieve commanders who failed to create a climate receptive for victims.
McCaskill, a member of the committee, said the Pentagon’s new data shows that a system that includes a role for commanders and holds them accountable with reforms can work for victims.
‘‘These numbers, while a comfort to no one, represent progress — and hopefully show that with new protections in place, and historic reforms on the way, victims will have the confidence to come forward, without us removing all accountability from commanders,’’ McCaskill said. ‘‘We know that the majority of military sexual assault survivors choose not to report their assaults — but this data suggests that the number of brave men and women choosing to pursue justice is increasing.’’