Brian K. Mahanna

Brian K. Mahanna provides strategic counsel to clients facing high-profile and complex investigations, corporate crises, regulatory scrutiny and other significant challenges when law and public policy converge. With years of government experience—including at the head of one of the nation’s largest and most active state attorney general’s offices—as well as private practice experience assisting companies who face dual federal and state regulators, Mr. Mahanna is uniquely positioned to assist clients with the challenges that accompany government actions. 

As chief of staff and deputy attorney general in the Office of the New York State Attorney General, Mr. Mahanna was responsible for the office’s operations and served as the primary liaison to the governor’s office, the state legislature, state agencies and other state attorneys general, including on complex multi-state investigations and litigation. He also supervised all major civil, regulatory and criminal cases, investigations, legal positions and initiatives for a state at the center of the nation’s financial sector and other important industries and managed the Executive Division’s special counsels and the communications, data analytics, legislative and intergovernmental affairs departments. He adds this experience and strategic insight to WilmerHale’s robust State Attorneys General Practice joining lawyers who are well known and respected among the AG ranks and who have handled matters on behalf of clients in 47 states, as well the District of Columbia and US Virgin Islands, and effectively coordinated and represented companies in multistate AG investigations.

In both the public and private sectors, Mr. Mahanna has litigated across multiple jurisdictions and overseen highly publicized corporate investigations and white collar cases. He possesses the specific skillset needed to address the wide-ranging and complicated legal and reputational challenges presented by the increasingly commonplace investigations, litigation and enforcement actions launched by state attorneys general. His extensive policy and litigation experience give him a deep understanding of how government agencies approach issues within their purview and critical insight into the regulatory frameworks that govern his clients’ industries. Understanding the inner-workings of federal, state and local prosecutors and regulatory authorities, Mr. Mahanna can work effectively with their offices to address issues in areas as diverse as consumer privacy and data security, sports gaming, broadband, alternative lending and crypto products, and non-traditional modes of transportation. 

Before joining the Office of the New York Attorney General, Mr. Mahanna was in private practice, working on complex civil and criminal matters, with a focus on municipal and state government-related proceedings. Prior to that, he served as senior adviser to former New York City Mayor Michael Bloomberg and as chief of staff and counsel to the deputy mayor for operations.

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  • Education

    • JD, Yale Law School, 2009

    • BA, Political Science and Metropolitan Studies, New York University, 2003

      magna cum laude
  • Admissions

    • New York

    • US District Court for the Eastern District of New York

    • US District Court for the Southern District of New York

  • Government Experience

    • State and Local Government

      Chief of Staff and Deputy Attorney General, New York
    • State and Local Government

      Senior Advisor to the Mayor, Office of the Mayor of New York City