It wasn't until after she left active duty, when she learned that her attacker had posted photographs of the assault online, that she sought an investigation.
Havrilla described the initial interview by the Army Criminal Investigative Division as "the most humiliating thing that I have ever experienced."
"I had to relive the entire event for over four hours with a male CID agent whom I had never met, and explain to him repeatedly what was happening in each one of the pictures," she said.
Months went by without any further word, Havrilla said. She said she "lived in constant fear that I might run into my rapist again or that he might retaliate against me in some way."
Ultimately, she said, her attacker said he had had consensual sex with her, and his chain of command declined to pursue adultery charges.
Former Army Spc. BriGette McCoy said she was sexually assaulted twice during her career, and later suffered anxiety, depression and suicide attempts. When she reported being sexually harassed, she said, she was "verbally and socially harassed, put on extra duties that conflicted with my medical profiles, and socially isolated."
Now, she said, "I have to say I no longer have any hope that the military chain of command will consistently prosecute, convict, sentence and carry out the sentencing of sexual predators in uniform."
Lewis is believed to be the first male survivor of rape to testify to the experience before Congress. While women in the military are more likely to be sexually assaulted than men, the preponderance of men in uniform means the numbers of men and women assaulted are similar.
Still, Lewis said, male victims are "marginalized."
"We … need to ensure that prevention efforts are inclusive of male service members," he said.
Lewis grew up in Baltimore and attended high school on Fort Meade before enlisting in the Navy in 1997. He was serving aboard the submarine tender USS Frank Cable as a fire control technician in August 2000, he said, when he was assaulted by a superior noncommissioned officer.
Lewis said the man had raped other sailors under the same command.
"It is only natural for commanders to want to believe that a crime did not happen," he said. "Making it disappear entails less risk for their careers. And not pursuing prosecution is much less disruptive for their units."
After his commanders learned of the attack, he was misdiagnosed, he said, with personality disorder and given a general discharge instead of an honorable discharge.
Now a graduate student at Stevenson University planning to attend law school, he said he carries the discharge "as a permanent symbol of shame, on top of the trauma of the physical attack, the retaliation and the aftermath.
"I fear it will be discussed when I apply for law school, when I apply to take the bar exam, even when I apply for a job. And I wonder what opportunities it may destroy for me.
"No one should be forced to undergo such painful and inappropriate treatment."