A Yale junior has filed a $20 million lawsuit against Gregory Korb ’09, whom she had accused of sexual assault in 2005, and against the University, in an effort to hold the University accountable for its handling of sexual assault cases and what the suit describes as its lax supervision of underage drinking.

The plaintiff’s lawyer said she is suing Korb for physical damages relating to the assault and for the psychiatric care she has received since. Yale is being sued for gross negligence, the victim’s mother said, for failure to prevent underage drinking, to provide enough security at campus events, to care for the victim and to adjust its policies since the incident took place during the opening days of the 2005 academic year.

Last October, Korb pleaded no contest to misdemeanor charges of third-degree assault and second-degree threatening and was sentenced to 18 months probation during which he is not allowed to come into contact with the victim or be on Yale’s campus. He had originally been charged with sexual assault in the first degree, assault in the second degree and unlawful restraint in the first degree.

David Rabin, the attorney for the plaintiffs, said that the lawsuit was filed in the Bronx County Courthouse in New York last week, but that the defendants had not yet been served the lawsuit.

Rabin said the purpose of the lawsuit against Yale is to force the University to take responsibility for the incident because the University’s policies created an environment that puts students at risk for sexual assault. The suit claims Yale did not respond well to the victim’s accusations against Korb and did not help enforce his probation.

“They [Yale] encourage some of these activities,” Rabin said. “They have no real rules or control on that campus. They have no personnel on campus to regulate such actions.”

University spokesman Tom Conroy said he could not comment because no one at the University has yet seen the suit. Korb’s lawyer, William Dow III ’63, declined to comment for this article.

Despite the plaintiff’s mother’s claim that both Yale and Korb were aware of the possibility of a lawsuit, Rabin said he had not previously send a letter of intent to either party. He said he looks forward to speaking with University officials once they are served the lawsuit in the coming days.

The plaintiff’s mother, who said she is also a plaintiff on the suit, said Yale should take responsibility for incidents that result from underage drinking on its campus. She also said she thinks University officials should have contacted her when the assault took place, once her daughter — who was over 18 at the time — had contacted the Calhoun College dean and master.

“The suit against Yale is to force them to change and punish them when they are unwilling to do so and punish them for not protecting their students,” the mother said. “I’ve seen masters and deans look away when there is alcohol being served at parties.”

The plaintiff’s mother said her daughter tried to contact Yale’s Executive Committee — the University’s undergraduate disciplinary body — but ExComm declined to speak to her, though she said she thinks Korb had contact with the committee.

Calhoun College Master Jonathan Holloway said he “cannot venture an answer” on the University’s policy about notifying parents of sexual assault victims but that in general “it depends on the circumstances and the student’s wishes.” Holloway declined to comment on the plaintiff’s allegations that the University is not strict enough in its policy against underage drinking.

The plaintiff was a Calhoun College resident at the time of the incident.

Rabin said one of the major complaints being lodged against Yale is that the University allowed Korb on campus in December 2006 — in violation of his probation, Rabin said — to fill out forms for his spring semester study abroad but did not then escort him off campus. He said the plaintiff found out that he was scheduled to perform with the sketch comedy group Suite 13 that same night to celebrate the court settlement that allowed Korb to avoid jail time. The plaintiff’s mother said her daughter notified the police, Dean of Student Affairs Betty Trachtenberg and Korb’s probation officer of his presence on campus. The group subsequently canceled the show.

“They [Yale officials] let him stay on campus. … They knew he had a conviction and had a court order to stay off campus, and that’s still how they acted,” Rabin said. “How about escorting him from the entrance to the campus to where he had to be?”

Amanda Lewis ’08, who said she is friends with Korb and had been friendly with the plaintiff in the past, said she thinks Yale should not be held responsible for the incident, especially since the case was settled before trial. She said the lawsuit is much more “sensational” than “legitimate.”

“Yale is extremely safe,” she said. “You can’t guard against what happens between two people in one room. … This has no bearing on Yale and its security.”

The lawsuit was first reported Tuesday in the New York Post.