Angela McCaskill uses sign language to address a news conference with help from an interpreter on Oct. 16, 2012, in Annapolis about being put on leave from her job after signing a petition to put Maryland’s same-sex marriage law on the ballot. (Brian Witte/Associated Press)

Gallaudet University’s chief diversity officer has accused her employer of violating a D.C. anti-discrimination law after a controversy last year that stemmed from her signing a petition that forced a public referendum on Maryland’s gay-marriage law.

Angela McCaskill alleges in a lawsuit filed Friday in U.S. District Court for the District of Columbia that the university mistreated her after a professor questioned her in October 2012 about her signature on the petition.

Her lawsuit accuses Gallaudet of violating anti-discrimination provisions of the D.C. Human Rights Act and of intentionally causing her emotional distress.

Gallaudet, a private university in Northeast Washington that receives federal support, is nationally known as a center of scholarship for the deaf and hard of hearing.

University spokeswoman Catherine Murphy said Monday that Gallaudet had no comment on the lawsuit.

McCaskill, who has worked for Gallaudet for more than 20 years, was placed on paid leave after officials learned that she signed the petition. That led to debate over whether Gallaudet had violated McCaskill’s free speech rights and whether signing the petition was an appropriate action for a university’s diversity officer. Maryland Gov. Martin O’Malley (D), a supporter of the gay marriage law, was among those who said the university overreacted.

Subsequently, Gallaudet President T. Alan Hurwitz said that McCaskill was welcome to return to her job but that she and the university community needed to “work together to respond to the concerns that have been raised.”

McCaskill has never said publicly whether she supports or opposes gay marriage, according to her attorney, J. Wyndal Gordon. She has maintained that her wish in signing the petition was simply to let the voters decide. In November 2012, Maryland voters upheld the state’s same-sex marriage law, with 52 percent voting to affirm it on ballot Question 6.

In the lawsuit, McCaskill said that the university demoted her when she returned to work. Her full title before the incident, she said, was deputy to the president and associate provost for diversity and inclusion, as well as chief diversity officer. Now, according to the lawsuit, she is the chief diversity officer.

McCaskill alleges that M.J. Bienvenu, a professor of American Sign Language and deaf studies, confronted McCaskill about her signature on Oct. 3, 2012, “in a very hostile manner,” accused her of being anti-gay and belittled her Christian beliefs. The lawsuit also alleges that the professor said she would bring the matter to the attention of top university officials in an effort to obtain “retaliatory disciplinary action” against McCaskill.

“I’ve nothing to hide. I did nothing wrong,” McCaskill replied, according to the lawsuit.

Bienvenu and Kendra L. Smith, a faculty member who heads the Gallaudet Department of Counseling, are both accused of defamation in the lawsuit. Efforts to reach Bienvenu and Smith for comment via e-mail Monday afternoon were unsuccessful.

McCaskill, in the lawsuit, said that she complained about Bienvenu’s assertions to Hurwitz but that the president did not investigate her complaints or take any action against the professor.

Gordon, McCaskill’s attorney, said the diversity officer was “prejudged” about her views by people at Gallaudet who did not know what those views actually were, leading to a controversy that damaged her professional reputation.

Gordon said he could not shed any light on McCaskill’s position on gay marriage. “I have no idea, and only she knows,” he said.

Peter Hermann contributed to this report