According to the lawsuit, Paul Nungesser was cleared of responsibility in Emma Sulkowicz's 2013 rape claim, as well as others that came to light after Sulkowicz went public with her allegations in various media interviews.
Her case drew national attention after she started carrying a mattress around campus to protest the school's handling of the complaint, saying she hoped to show how "flawed" the university disciplinary system is when it comes to sexual misconduct cases.
CNN does not usually name individuals in sexual assault cases, but in this instance, both parties have spoken publicly about their experience. They have also both said in separate interviews
with The New York Times that Nungesser was cleared of responsibility in a disciplinary hearing.
Nungesser, an international student from Germany, filed a federal discrimination lawsuit last week against the school; its president, Lee Bollinger; and the visual arts professor who oversaw Sulkowicz's mattress project, "Carry That Weight," as part of her senior thesis.
The lawsuit alleges the defendants violated Nungesser's right to an education free of gender-based discrimination by allowing Sulkowicz to speak out against him after he had been cleared of wrongdoing. During an April 2014 news conference at Columbia University, Sen. Kirsten Gillibrand stood alongside Sulkowicz as she called Nungesser a "serial rapist" and said she fears for her safety while he's still on campus.
The harassment continued, the lawsuit claims, when Columbia visual arts professor Jon Kessler let Sulkowicz "transform her personal vendetta" into a "Columbia-sponsored calumny" by supporting "Carry That Weight" for her senior thesis, allowing her to earn school credit through "this outrageous display of harassment and defamation."
Bollinger also commented on the case in a 2014 New York Magazine profile
of Sulkowicz, now a senior at Columbia.
"This is a person who is one of my students, and I care about all of my students. And when one of them feels that she has been a victim of mistreatment, I am affected by that. This is all very painful."
The defendants "had the power, as well as the legal and contractual obligation" to protect Nungesser, who is also a senior, the lawsuit claims.
"By refusing to protect Paul Nungesser, Columbia University first became a silent bystander and then turned into an active supporter of a fellow student's harassment campaign by institutionalizing it and heralding it."
Columbia University declined to comment on the lawsuit. The school also declined to confirm the outcome of Nungesser's disciplinary proceedings.
"As we have said consistently, we do not and have not commented on individual students or disciplinary cases not only because of federal student privacy law, but also because of our ethical responsibility to ensure all current and future students have confidence that the university will never publicly discuss private matters they share when interacting with counselors and support staff, the campus disciplinary process or other resources we provide to them," spokesman Robert Hornsby said in statement.
Kessler also declined to comment on the lawsuit.
The case has produced dueling narratives from both sides in national media outlets. The most recent came from Nungesser in a Daily Beast article titled
, "Columbia Student: I Didn't Rape Her," in which he shared a long exchange of Facebook messages to support his claim that their sex was consensual.
Some of those exchanges were included in the lawsuit, but Sulkowicz told CNN they were taken out of context in the suit.
She also balked at the idea that Nungesser would sue the school or her professor "for allowing me to make an art piece."
"It's ridiculous that he would read it as a 'bullying strategy,' especially given his continued public attempts to smear my reputation, when really it's just an artistic expression of the personal trauma I've experienced at Columbia," Sulkowicz wrote in an email. "If artists are not allowed to make art that reflects on our experiences, then how are we to heal?"
The project essentially consists of Sulkowicz carrying a twin-size mattress wherever she goes on campus, but not off campus. She's allowed to accept help carrying the object but does not allow herself to ask for help.
Nungesser's complaint seeks damages to be determined at trial for harm to his reputation, loss of educational opportunities and future career prospects.