Mary J. Hahn

Mary Hahn is a visiting lecturer in law, senior research scholar, and Peter Gruber Senior Rule of Law Fellow at Yale Law School. From 2010 to 2026, Hahn served as acting deputy chief and trial attorney for the Criminal Section and as trial attorney in the Housing and Civil Enforcement Section of the U.S. Department of Justice, Civil Rights Division. In those positions, she litigated fair housing and fair lending cases and prosecuted criminal civil rights violations and hate crimes. She prosecuted several significant hate crimes, including the bias-motivated mass shootings at the Tree of Life Synagogue in Pittsburgh and the Mother Emanuel Church in Charleston. She also served as counsel for the Office of the Associate Attorney General from 2021 to 2022. 

Before joining the Department of Justice, Hahn litigated complex civil rights cases, including fair housing, fair lending, employment discrimination, and Section 1983 cases involving police misconduct and 1st Amendment violations. She was a fellow at the ACLU, an associate at Relman Colfax PLLC, and the director of the Fair Housing Project for the Washington Lawyers’ Committee for Civil Rights and Urban Affairs. At Yale Law School, Hahn previously served as the Robert M. Cover-Allard K. Lowenstein Fellow in International Human Rights Law, supervising the Balancing Civil Liberties and National Security after 9/11 Clinic and the Lowenstein Clinic. She clerked for then-Chief Judge John M. Walker Jr. on the U.S. Court of Appeals for the 2nd Circuit. She received a B.A. from Harvard University and a J.D. from Yale Law School.