Karen Patton Seymour

Karen Patton Seymour is a member of the Firm’s Management Committee and was formerly the Co-Managing Partner of Sullivan & Cromwell’s Litigation Group. Her practice focuses on commercial litigation, white-collar criminal defense and internal investigations. She also represents clients in complex federal and state civil litigation.

She has represented individuals, corporations and financial institutions in state and federal investigations and proceedings involving allegations of:

• securities fraud and insider trading
• violations of the Foreign Corrupt Practices Act
• OFAC sanctions
• healthcare fraud
• criminal antitrust violations
• money laundering violations

Ms. Seymour has tried numerous jury and bench trials in federal court and argued many appeals before the U.S. Court of Appeals for the Second Circuit.

She has in-depth experience representing corporations and individuals outside of the United States in responding to U.S. inquiries and investigations, and assisting in complex international investigations.

Ms. Seymour is admitted to practice before the U.S. Supreme Court, two U.S. Courts of Appeal, and the Court of Federal Claims, as well as the New York State Courts and the U.S. District Courts for the Southern and Eastern Districts of New York.

Government Service

From 2002 to 2004, Ms. Seymour served as the chief of the Criminal Division for the U.S. Attorney’s Office for the Southern District of New York, where she supervised 165 federal prosecutors and oversaw all criminal investigations and prosecutions in the district, including the investigations of corporate fraud involving WorldCom, ImClone and Adelphia. She was lead trial counsel for the government in the prosecution of Martha Stewart and Peter Bacanovic.

During her first tenure in the U.S. Attorney's Office from 1990 to 1996, she prosecuted a wide variety of cases and served as Chief of the General Crimes Unit.

Ms. Seymour frequently lectures on FCPA, corporate fraud, internal investigations, securities enforcement, business ethics and other topics.

Professional Activities and Community Involvement

• Departmental Disciplinary Committee Panel Chair, Supreme Court Appellate Division, First Department
• Chair of the New York City Bar Association’s Committee on White Collar Criminal Law
• National Vice Chair of the ABA Criminal Justice Section White Collar Crime Committee
• Attorney Grievance Committee for the U.S. Court of Appeals for the Second Circuit
• Board Member, Vera Institute of Justice
• Trustee, The Nature Conservancy, New York State
• New York District Attorneys' White Collar Crime Task Force, 2012
• Member, American Law Institute. Adviser on Restatement of the Law Third, Conflict of Laws Project

Rankings and Recognitions

• Chambers USA: America’s Leading Lawyers for Business – recognized as a Leading Litigator in White-Collar Crime & Government Investigations (2006-2015) and in Financial Services Regulation: Banking (Regulatory Enforcement & Investigations) (2007-2015)
• Euromoney’s Expert Guides – ranked as one of the top thirty white collar crime attorneys in the United States
• Euromoney’s Benchmark Litigation – ranked as one of the “Top 10 Women Litigators” in Top 250 Women in Litigation (2012-2016)
• Euromoney’s Benchmark Litigation– recognized as a Star for White-Collar Litigation (National) and Litigation (New York) (2008-2016)
• Euromoney’s Guide to the World’s Leading White Collar Crime Lawyers (2008)
• New York Super Lawyers – selected as one of the top New York lawyers in the field of Criminal Defense: White Collar (2006-2015)
• New York Super Lawyers – selected as one of “The Top 50 Female” lawyers (2007-2010, 2012, 2013, 2014, 2015)
• The Best Lawyers in America – recognized as a leading litigator in the areas of White-Collar Criminal Defense (2007-2016), Commercial Litigation (2007-2016), Litigation - Regulatory Enforcement (SEC, Telecom, Energy) (2012-2016), Bet-the-Company Litigation (2016) and Litigation - Securities (2012-2016)
• The Legal 500 United States – recommended Lawyer for White-Collar Criminal Defense (2007-2015) and for Corporate Governance and SEC Investigations (2007)
• Who’s Who Legal: The International Who’s Who of Business Lawyers and The International Who’s Who of Business Crime Lawyers – recommended Lawyer for Business Crime Defense (2007-2009, 2011)
• Lawdragon – ranked as one of the top 3,000 lawyers in the United States (2009-2010); selected as one of “100 Lawyers You Need to Know in Securities Litigation” (2008); ranked as one of the top 500 lawyers in the United States (2005, 2007, 2012, 2013, 2014, 2015)
• New York Post – ranked as one of the 50 most powerful women in New York (November 21, 2004)
• 2012 Gould Award for Outstanding Oral Advocacy, Office of the Appellate Defender
• 2012 Law & Society Award, New York Lawyers for the Public Interest
• 2009 Burton Award for Legal Achievement – Legal Writing
• 2009 Robert M. Morgenthau Award for outstanding legal career and improving the lives of children in New York

Practices and Capabilities

• Litigation
• Antitrust
• Appellate
• Congressional Investigations
• Criminal Defense & Investigations
• FCPA & Anti-Corruption
• Financial Services Investigations & Litigation
• International Trade & Investment/CFIUS
• Securities
• Whistleblower Litigation and Workplace Investigations
• AML & Sanctions Enforcement and Compliance

Education

• 1987, University of London, LL.M.
• 1986, The University of Texas School of Law, J.D.
• 1983, Southern Methodist University, B.A./B.S.

Bar Admissions

• New York

See Library Tab for articles, publications and presentations by Karen Patton Seymour