OVERVIEW

Mary is a Partner in Hausfeld’s Washington, DC office. Her focus lays in complex litigation, with an emphasis in the human rights, immigration, consumer protection, and antitrust fields. She has litigated numerous class action matters in state and federal courts across the nation, from claim development to settlement, and is committed to representing plaintiffs in groundbreaking challenges in pursuit of social good.

Before joining Hausfeld, Mary represented clients in trial and appeal in defense of immigrants’ rights. For example, Mary helped settle a class action against unlawful immigration raids; led a novel multi-claimant challenge to an unlawful asylum ban; and successfully enjoined harmful immigration regulations. While serving as an immigration public defender at Brooklyn Defender Services, Mary also litigated dozens of habeas corpus petitions, securing noncitizens’ release from detention due to civil or constitutional violations.

Mary first gained experience at a global law firm in Washington, D.C., where she served as counsel in a large-scale data breach class action and a variety of international trade and commercial litigation matters. She also clerked for the U.S. Court of Appeals for the Third Circuit. She earned her J.D. from Stanford Law School, where she was a Senior Editor for the Stanford Law Review.

Working towards a diverse, equitable, and inclusive world is paramount to Mary who is an active member of our Social Inclusion working group.

Clients

Mary represents a range of individuals, consumers, and state attorneys general in cases challenging corporate wrongdoing.

EDUCATION

Stanford Law School, J.D., 2014

University of Michigan, BBA, 2010

BAR ADMISSIONS

District of Columbia

New York

United States District Court for the Southern District of New York

United States District Court for the Northern District of Illinois

United States District Court for the District of Columbia

United States Court of Appeals for the Second Circuit

United States Court of Appeals for the Fourth Circuit

United States District Court for the Western District of Texas

United States Court of International Trade

AFFILIATIONS

American Bar Association - Antitrust Section, Member

American Bar Association – Section of Civil Rights & Social Justice, Member

WHAT OTHERS SAY

Best Lawyers

One to Watch since 2024
- Antitrust Law
- Litigation - Antitrust

Experience

Antitrust/Competition

In re Diisocyanates Antitrust Litigation – Hausfeld represents a class of manufacturers in claims against major industrial suppliers for conspiring to artificially inflate prices of the chemicals methylene diphenyl diisocyanate (MDI) and toluene diisocyanate (TDI).
In re Fragrance Direct Purchaser Antitrust Litigation - Hausfeld serves as Co-Lead Counsel for a class of direct fragrance purchasers against the four largest suppliers of fragrances and fragrance ingredients in the world, International Flavors & Fragrances Inc. (IFF), Symrise AG, Givaudan SA, and Firmenich SA, for potential price fixing and other anticompetitive conduct in the fragrance industry.

Environment & Product Liability

Among others, Mary represents a state attorney general’s office in a cutting-edge challenge against harmful levels of toxic metals in baby foods.

Human Rights

Padre et al. v. MVM - Hausfeld represents families that were unlawfully separated pursuant to the unconstitutional family separation policy implemented during the first Trump administration. The defendant in this class action lawsuit is MVM, Inc., the private security contractor that transported thousands of migrant children away from their parents. The plaintiffs bring human rights claims for enforced disappearance, torture, and cruel and inhumane treatment under the Alien Tort Statute, among other claims.
Kashef v. BNP Paribas SA – Mary is part of the Hausfeld team representing a class of refugees, asylees, and other victims of human rights abuses against a French bank that violated U.S. sanctions and enabled the Sudanese government to commit acts of genocide.

Mary Sameera Van Houten Harper