WASHINGTON — The number of reported sexual assaults in the military shot up by more than 50 percent this year, an increase that defense officials say may suggest that victims are becoming more willing to come forward after a tumultuous year of scandals that shone a spotlight on the crimes and put pressure on the military to take aggressive action.
A string of high-profile assaults and arrests triggered outrage in Congress and set off months of debate over how to change the military justice system, while military leaders launched new programs intended to beef up accountability and encourage victims to come forward.
According to early data obtained by the Associated Press, there were more than 5,000 reports of sexual assault filed during the fiscal year that ended Sept. 30, compared with 3,374 in 2012. Of those 2013 reports, about 10 percent involved incidents that occurred before the victim got into the military, up from just 4 percent only a year ago. That increase, officials said, suggests that confidence in the system is growing and that victims are more willing to come forward.
Asked about the preliminary data, defense officials were cautious in their conclusions. But they said surveys, focus groups, and repeated meetings with service members during the year suggest that the number of actual incidents — from unwanted sexual contact and harassment to violent assaults — has largely remained steady.
‘‘Given the multiple data points, we assess that this is more reporting,’’ said Colonel Alan R. Metzler, deputy director of the Pentagon’s sexual assault prevention and response office. He also noted that more victims are agreeing to make official complaints, rather than simply seeking medical care without filing formal accusations.
The military has long struggled to get victims to report sexual harassment and assault in a stern military culture that emphasizes rank, loyalty, and toughness. Too often, victims have complained that they were afraid to report assaults to ranking officers or that their initial complaints were rebuffed or ignored.
As a result, the crime has been vastly underreported, a fact that became evident when officials announced earlier this year that an anonymous survey had revealed that about 26,000 service members reported some type of unwanted sexual contact or sexual assault.
According to the latest numbers, the increase in reports across the services ranges from a low of about 45 percent for the Air Force to a high of 86 percent for the Marines, the smallest service. The Navy had an increase of 46 percent and the Army, by far the largest military service, had a 50 percent jump.
Jill Loftus — director of the Navy’s sexual assault program, which also includes the Marine Corps — said the increase in reporting also suggests that more service members are starting to understand what types of behavior constitute harassment or assault.
She said that based on Navy surveys, ‘‘we are not seeing a perception that the number of incidents are going up.’’
‘‘More likely, we have people who understand what sexual assault is,’’ she said. And, she said, officials are hearing that more people are comfortable coming forward.
Still, military leaders acknowledge that a lot of work remains to be done.