Erin Cavalier is seen at Catholic University, where she recently finished her sophomore year. (Jahi Chikwendiu/The Washington Post)

Erin Cavalier downed a couple of glasses of wine and a­ few shots of tequila, grabbed a water bottle filled with vodka and Sprite, and headed out from her dormitory to celebrate the end of her first semester at the Catholic University of America.

After polishing off the mixed drink, the 18-year-old from Northern California started drinking beer at a party. After midnight, in what she describes as a stupor, she asked if someone could help her walk to her room on the campus in Northeast Washington. A male student she considered an acquaintance volunteered. She says she blacked out.

Back in her room, Cavalier recalled, she regained awareness. The man was on top of her, she said, raping her. Cavalier said she was too drunk to agree to sex. “I never consented,” she said.

The man saw it differently, telling investigators that Cavalier was a willing participant in a sexual encounter after he walked her home and she signed him into her dorm. The man was never charged with a crime, and an initial D.C. police report said evidence indicated there was mutual consent. But that was not nearly the end of it.

What happened that night in December 2012 set off a chain of events that a year and a half later pushed the Vatican’s university in America into a fierce national debate over how colleges respond to allegations of sexual assault. In growing numbers, students such as Cavalier are stepping forward to force public scrutiny of an issue that has quietly affected colleges for decades.

Some campus sex-assault cases are clear-cut. But many emerge from murky circumstances involving alcohol, parties and young adults living away from home for the first time. Under federal law, sexual violence on campuses is not only a crime but also a form of illegal discrimination requiring speedy remedy. Students are increasingly demanding action from their schools, which in turn face heightened pressure from the government to investigate and resolve the allegations.

Reports are growing

Reports of forcible sex offenses on college campuses nationwide grew from about 2,600 in 2009 to more than 3,900 in 2012, according to federal data, up 50 percent. That doesn’t mean campuses became that much more dangerous in those years; experts say students who in previous generations probably would have remained silent about what they experienced are now coming forward. Colleges, too, have become more thorough in documenting the problem and teaching students that incapacitation, through alcohol or drugs, prevents effective consent.

The trend is likely to accelerate. President Obama drew public attention to campus sex assaults this year through a White House task force. Lawmakers have invited survivors of sex assaults to Capitol Hill to advise them on legislation.

But there are at least two sides to every allegation. Brett A. Sokolow, president of the National Center for Higher Education Risk Management, said he worries that many students accused of sexual misconduct are “getting much less of a fair shake than they used to.” Accused students often say they are the victims.

Sokolow said some cases that in years past would have been considered “drunk sex” are now being examined for disciplinary violations. Colleges, he said, “have got to get this thing just right.”

Cavalier, now 20 and a rising junior, said she wants Catholic to reform how it responds to reports of sexual assault. “As a survivor,” she said, “I know how horrible it can go.”

The Washington Post generally does not identify those who report being victims of sexual assault. But Cavalier chose to go public with her story to illuminate a complaint she filed with the federal government alleging that Catholic University mishandled her case, violating a 1972 law called Title IX that bars gender discrimination.

The complaint alleges that Cavalier was unfairly “forced to lobby, argue and fight for a grievance hearing,” an internal misconduct trial held behind closed doors.

Catholic initially decided a hearing was unwarranted but reversed itself after several months of back and forth with Cavalier and her representatives. A university hearing board concluded in October that there was insufficient evidence to find that Cavalier’s alleged attacker had violated the student conduct code.

“The university is confident that it acted appropriately in investigating and resolving the issue that gave rise to the student’s complaint,” Catholic spokesman Victor Nakas said.

Federal investigations

Catholic, with 6,700 students, was founded under a papal charter in 1887. It is one of about 60 institutions of higher education under federal investigation for their handling of reports of sexual violence. They range from Harvard Law School and Princeton University to the Butte-Glenn Community College District in California and the West Virginia School of Osteopathic Medicine, according to federal officials, who disclosed a comprehensive catalogue of investigations for the first time on May 1.

Four Virginia schools are under investigation: the University of Virginia, the College of William and Mary, James Madison University, and the University of Richmond. So is Frostburg State University in Western Maryland. Federal investigations begin after individuals file complaints or the Education Department initiates a compliance review. Federal officials said they have drawn no conclusions that any of the schools are violating the law.

After Catholic was named on the federal list, Cavalier recounted what happened to her on Dec. 15, 2012, and the aftermath, in an interview with The Post at her attorney’s office in downtown Washington. She signed a statement that waived her federal privacy rights — giving the university permission to disclose information about her case — but Catholic officials declined to discuss any specifics, citing the federal investigation and the school’s “obligations to both of the students who are parties to the matter.”

The student Cavalier says raped her could not be reached through telephone calls to his family residence, and he did not respond to a message via Facebook. The Post is not identifying him because he has not been charged with a crime, and because of the university hearing board’s conclusion that there was insufficient evidence to find violations of the student conduct code. The man’s father said there is much more to the case than Cavalier’s version. “There are lots of facts not being brought out,” he said, declining to comment further.

The sixth of seven children in her family, Cavalier attended Catholic schools while growing up in the San Francisco Bay area. She said she came to Catholic University to play lacrosse and also was drawn to its location in the nation’s capital. She belongs to the College Republicans, is majoring in politics and wants to explore careers in counterterrorism.

The night in question

On the Friday night after her first set of final exams, Dec. 14, 2012, Cavalier was doing laundry in her dorm, preparing to fly home. At about 9 p.m., she bumped into a friend who invited her to a gathering at another dorm. She believes she started drinking at 10 p.m. and stopped at about 12:30 a.m. at a party with about a dozen other students.

It was something all too common on college campuses: a binge.

Cavalier described herself that night as “blackout drunk,” saying she “obviously had way too much to drink, and it was not a good idea on my end.”

She said she was almost falling asleep on a couch when she realized she needed to leave. “I kind of announced I would like someone to walk me home,” she said. She said she recalls little else until she realized she was being attacked in her bed. After the man left, Cavalier went into a bathroom. A resident assistant found her there, crying.

“She asked what happened,” Cavalier said. “I said I had been raped.”

A blur of activity ensued: The RA called for help. Campus police responded. She went to Washington Hospital Center and saw a nurse specializing in sexual-assault examinations. An advocate from Network for Victim Recovery of D.C. arrived to help. Cavalier called her parents.

D.C. police interviewed her, and she said she decided not to seek criminal charges.

“They literally asked me upfront while I was highly intoxicated and absolutely traumatized in every way,” Cavalier said. “The idea of going through a legal process sounded horrible.” But Cavalier disputed a D.C. police report filed at 3:03 a.m. that described the incident, according to a preliminary statement, as consensual sex.

“While I cannot tell you exactly what I said that night to the police or really any other person, the people that I spoke to that night that I trust, my parents, my friends . . . have all told me that I said I was raped,” Cavalier said. “No consent.”

Lindsey Silverberg, the advocate who joined Cavalier at the hospital, confirmed that account.

A toxicology report from the hospital showed that at 8:28 a.m., Cavalier’s blood alcohol level was 0.097, above the 0.08 legal threshold for drunk driving. Because blood alcohol level eventually diminishes after a person stops drinking, Cavalier’s attorneys believe hers was at or above 0.2 at the time of the incident, a high level of intoxication.

That afternoon, Cavalier flew home to California.

Two days later, a Catholic administrator sent her an e-mail. “I wanted to check in and see how you were doing,” Rachel Wainer, an assistant dean of students, wrote on Dec. 17, according to a copy of the e-mail Cavalier provided. “I understand that you may have questions or concerns, and I would be more than happy to connect with you.”

Cavalier replied a few days later, suggesting times to talk by phone that week. But she said she didn’t hear back from Wainer or anyone else throughout the winter break. When she returned to Washington, Cavalier e-mailed Wainer, asking to meet. “Now that I am back on campus,” she wrote on Jan. 14, 2013, “I would like to get back to this.”

“We can absolutely meet today,” Wainer replied within a few minutes. “I am sorry we were not able to touch base before the University closed for the Christmas holiday.” The e-mail appears to confirm a four-week gap in communication between Catholic and Cavalier.

Wainer declined to discuss the case.

Lawrence J. Morris, Catholic’s general counsel and a retired Army colonel, also declined to comment on Cavalier’s case. But Morris said the university strives to connect quickly with any student who reports a sex assault, even during vacations. “You do your best to get to the person as immediately as we can,” he said, “and we persist regardless of what the immediate circumstances will be.”

When Cavalier met with Wainer, the assistant dean explained her options: pursue a criminal charge, file an internal misconduct complaint, do both or do neither. Cavalier chose to seek internal discipline.

On Jan. 16, campus police interviewed her. On March 20, the dean of students, Jonathan C. Sawyer, told her there was not enough evidence to hold a hearing on her complaint. The university, he said, would issue an order for the two students to avoid contact with each other and take other steps, if necessary, to preserve distance between them.

Stunned and doubtful

Cavalier said she was stunned. Until that point, she had considered Catholic a neutral arbiter. But the dismissal of her complaint left her in doubt. “They didn’t even allow me to have a chance to prove that I was raped,” she said. “That’s the part that made me feel very alone.”

Cavalier then connected with Matt Ornstein, a lawyer with the victim recovery network. He helped her obtain the toxicology report from the hospital and attached it to an appeal, saying the university should look at whether Cavalier had been too drunk to have the capacity to consent.

On April 10, campus police reinterviewed Cavalier. Ornstein, who was present, said one of the investigators told Cavalier some alcoholics are able to consent to sex even though they are drunk.

“I was upset when they explained that,” he said. “You know, Erin’s not . . . a 50-year-old career alcoholic who’s been dealing with these things her whole life and has developed some incredible tolerance or has some sort of natural immunity to alcohol.”

Ornstein said the investigators were skeptical of Cavalier’s incapacitation claim because of what they viewed as a lack of corroboration from witnesses. The lawyer asked to see a report on what witnesses said. Investigators said they would forward his request.

The case then stagnated. Cavalier continued her studies and did her best to avoid the other student on campus. In California, her parents were dismayed. The spring semester of 2013 was slipping away, and the issues seemed unresolved.

“It was a long, frustrating period of time,” said her father, Mark Cavalier, a financial adviser. He flew to Washington in May and hired lawyer Kobie Flowers to explore legal options.

On July 8, Ornstein obtained the internal report from campus police that he had requested in April. Cavalier and her attorneys said they were struck by statements from witnesses at the party that seemed to support her claim of drunken incapacitation, such as “she was staggering,” and she “was very drunk and falling asleep.”

They scheduled a meeting with Sawyer and Morris on Aug. 21 to demand a hearing, with Cavalier’s father present. Almost immediately, Sawyer told them the university would grant their request.

Preparing for the hearing

The approach of the Oct. 3 hearing underscored questions about how a university inquiry differs from a court of law: Who could attend? Who could ask questions? What were the rules of evidence? Who would judge?

Catholic’s system, according to Morris, provides for a hearing board of four administrators or faculty members. The accuser and accused are given equal access to witness statements and other documents. During the closed and confidential proceedings, students must speak for themselves but are allowed to have a lawyer with them as an adviser. Only the board is allowed to question witnesses, but the accuser and the accused may suggest questions through notecards.

The board decides cases on a standard of “preponderance of the evidence” — that is, whether it is more likely than not that a student broke the university’s rules. The standard — lower than the “beyond reasonable doubt” burden of proof for a criminal conviction — follows federal guidance issued in 2011. Critics say the preponderance standard is unfair to the accused.

Morris said the goal of the process is to “remove or diminish any obstacles” to delivery of the best possible educational experience. “Remember, it is unrealistic for a university investigative and adjudicative process to bring perfect justice in these cases,” he said. Public courts of law, he said, are better equipped for that task.

Cavalier said Catholic failed to make clear with enough advance notice that her parents were entitled to attend the hearing in the university’s Pryzbyla student center. They couldn’t make it; Flowers and Ornstein accompanied her.

The hearing lasted about six hours, Cavalier said. She sat across the room from the accused student.

The board’s verdict

The board issued a verdict six days later, finding that “no force was involved,” that Cavalier was “not incapable of giving consent,” and that the male student “would not reasonably have thought” that Cavalier was incapacitated or unable to give consent. The man was cleared.

On Dec. 20, Cavalier filed an eight-page Title IX complaint with the Office for Civil Rights of the Education Department. The federal investigation began on Jan. 8. A key question is whether Catholic’s response to the sexual-assault report was prompt and equitable. Federal guidelines say colleges typically take 60 days to investigate cases, but that is not a requirement.

Before all this happened, Cavalier said, she knew of Title IX only as a law that prohibited gender bias in college sports. Now, like a growing number of students, she has learned of its relevance to sexual violence.

Cavalier wants to help spread the word, saying she is “totally up for being an activist.” She recently helped organize a Take Back the Night event on campus to promote prevention of sexual violence. She also is resolved to stay at Catholic and finish her degree.

“I’m not going to allow something he did — and something that the administration maybe didn’t take care of correctly — I’m not going to let that take away from my college experience,” she said. “Because that’s not fair.”