William J. Vigen

William Vigen

Bill Vigen is an experienced trial attorney who has represented clients in high-profile antitrust litigation and government investigations. Bill was a trial attorney at the U.S. Department of Justice, Antitrust Division, Criminal Section II, where he litigated criminal prosecutions and led complex investigations against major companies and individuals for antitrust violations. Prior to his service in the public sector, Bill was an attorney at a large, prominent law firm, where he worked on teams representing multinational companies and senior executives in complex civil litigation and white collar criminal defense, with a primary focus on antitrust.

Earlier in his career, Bill served as a law clerk to the Honorable M. Blane Michael of the United States Court of Appeals for the Fourth Circuit.

Related Practices


Government Experience

  • Trial Attorney, U.S. Department of Justice, Antitrust Division, Criminal Section II

Representative Matters

  • Argued successfully on behalf of the U.S. government against a provider of dialysis services to defeat motion to dismiss criminal indictment alleging agreement not to solicit employees; litigated and argued multiple motions in limine; second-chaired trial and cross-examined only defense witness
  • Obtained $100 million statutory maximum fine in negotiated Deferred Prosecution Agreement with a medical practice for dividing the market for cancer care
  • Trial attorney for a broadcast television network alleging $1 billion in defamation damages; argued evidentiary motions
  • Second-chaired three-week equitable distribution trial for plaintiff in divorce of founder, chair, and CEO of a publicly traded company, requiring complex valuation of assets; directed expert valuation witness and cross-examined defense expert valuation witness
  • Lead attorney for Fortune 50 company on rapid investigation and production in response to USAO and SEC subpoenas as part of high-profile government investigation
  • Advised Fortune 200 company on possible criminal antitrust violation involving international markets; interacting with EU counsel and company on strategy
  • Pro bono representation in Maryland Court of Special Appeals, Montgomery County Circuit Court, DC parole revocation hearing, and DC landlord-tenant court




  • J.D. University of Virginia School of Law 2009
    • Order of the Coif
    • Articles development editor, managing board, Virginial Law Review
    • John M. Olin Program in Law and Economics Scholar
  • B.A. Economics summa cum laude University of South Carolina Honors College 2006

Bar Admissions

  • District of Columbia

Court Admissions

  • U.S. Court of Appeals for the Fourth Circuit
  • U.S. District Court for the Eastern District of Michigan

Clerk Experience

  • M. Blane Michael U.S. Court of Appeals for the Fourth Circuit

Professional Memberships and Activities

  • Board member, Capitol Hill Community Foundation


  • DOJ Antitrust Division, Award of Distinction, 2022



  • Capitol Hill Community Foundation