Government Experience

  • Assistant United States Attorney, United States Department of Justice, District of Maryland

Bar Admissions

  • Maryland

Court Admissions

  • U.S. Court of Appeals for the Fourth Circuit
  • U.S. District Court for the District of Maryland
  • U.S. Supreme Court


  • J.D., Columbia University School of Law, 1985
  • M.A., University of Sussex, UK, 1982
  • B.A., magna cum laude, Princeton University, 1980

Judicial Clerkships

  • Honorable Francis D. Murnaghan, Jr., U.S. Court of Appeals for the Fourth Circuit, 1985 - 1986


  • American Bar Association

    Federal Bar Association

    Board of Advisors for the BNA White Collar Crime Reporter

    Maryland State Bar Association, Environmental Law Section

    Fourth Circuit Judicial Conference
T +1 410.244.7563
F +1 410.244.7742

W. Warren Hamel


Warren Hamel is the chair of Venable's Investigations and White Collar Defense Practice Group. Warren represents clients in white collar criminal defense, environmental criminal defense, and civil enforcement matters, conducting internal investigations, general civil litigation, and commercial and contract disputes. He advises clients on compliance and internal control issues, including records and information management and electronic discovery, whistle-blower issues, and a range of Sarbanes-Oxley-related matters. Warren served as an Assistant U.S. Attorney in the U.S. Attorney's Office for the District of Maryland from 1990 to 2002. From 1997 through 2001, he served as Chief of the Environmental Crimes and Enforcement Unit of the U.S. Attorney's Office for the District of Maryland, where he was responsible for investigation and prosecution of a broad variety of criminal cases and litigation of civil enforcement and defense cases under the Clean Water Act, Clean Air Act, RCRA, and a range of other environmental and conservation statutes.

Warren also has extensive experience investigating, prosecuting, and defending fraud and corruption cases, including cases involving mail and wire fraud, bank fraud and fraud on federally funded programs, the Foreign Corrupt Practices Act, the Food, Drug and Cosmetic Act, and False Claims Act. Recent Foreign Corrupt Practices Act, False Claims Act, and other investigations have taken Warren to locations in Europe, South and Central America, Africa, and India.

Warren has also represented various print and broadcast media in litigation matters, including libel cases, reporter's privilege cases, and press access matters in federal court. Warren has provided pre-publication advice and review to local, national, and international media companies.

Representative Matters

Internal Investigations
  • Led an international team conducting an internal investigation in Brazil for a multinational corporation into allegations involving financial integrity issues in its Brazilian subsidiary.
  • Conducted an internal investigation with Venable‚Äôs Legislative Practice into business activity of companies providing oil logistics support services to energy companies in Nigeria, in order to respond to a U.S. Senate Permanent Subcommittee on Investigations inquiry and a shadow investigation by DOJ into potential Foreign Corrupt Practices Act violations. The DOJ investigation resulted in no action.

Criminal Defense
  • Represented a company in USFWS and DOJ investigation of illegal importation of CITES-protected materials for manufacture of high-end consumer goods. Investigation closed with no action.
  • Represented an individual in tax fraud investigation by IRS and DOJ, resulting in favorable outcome after plea negotiations and a contested sentencing.
  • Represented a law firm in federal grand jury investigation of alleged unlawful immigrant visa submissions to Department of State. Investigation closed with no action.

False Claims Act
  • Defended a national logistics company in False Claims Act investigation into allegations of overcharging in a nationwide Department of Defense contract. After over a year of discovery, advocacy, and negotiation, settled claims on favorable terms on behalf of the client. The original demand by the government and the qui tam relators was in excess of $1 billion. Under terms of the settlement, the company and a co-defendant paid a total of $13 million, and the False Claims Act allegations against the companies have been dismissed with prejudice, waived, and released.
  • Represented a large nonprofit in a qui tam False Claims Act case; investigation resulted in dismissal of complaint, and client settled separate retaliation claims with relator and audit claims by federal grant-making agency.
  • Co-led a Venable team in defending a five-year investigation by DOJ and the FDA into criminal and civil claims against an India-based generic drug manufacturer, ultimately negotiating a comprehensive settlement that included resolution of the criminal investigation and a qui tam False Claims Act case, for which the company paid a total of $500 million in fines, and which allowed the company to exercise its first-to-file right to market atorvastatin (generic Lipitor) in the United States.
  • Represented a chief marketing officer for a pharmaceutical company in a DOJ investigation of alleged off-label promotions, potential violation of the False Claims Act, and violations of the anti-kickback statute in promotion of a branded drug. The investigation was terminated without charges against the client.

Foreign Corrupt Practices Act
  • Represented an individual foreign national in a DOJ investigation of potential FCPA violations for bribery in connection with port maintenance contracts in Panama.
  • Helped an international media corporation devise and implement a comprehensive FCPA Compliance Program, including creating policy, training employees, and implementing compliance and audit systems.

Environmental Criminal and Civil Enforcement
  • Represented one of the largest manufacturers of cast iron and ductile pipe in the U.S., in a multi-jurisdictional criminal investigation/prosecution focused on environmental and safety-related violations. Negotiated plea agreements in three of the five jurisdictions in which criminal charges were brought by DOJ. Also negotiated ground-breaking consent decree to address hundreds of civil and administrative violations at more than 20 facilities nationwide, using an agreed-upon third-party consultant to evaluate internal company audits and make recommendations of violations and suggested penalties.


Warren served on the Board of Trustees of the Chesapeake Bay Trust from 2006 to 2015 and was Chairman of the Board from 2011 to 2014. He also serves on the board of The Francis D. Murnaghan, Jr. Appellate Advocacy Fellowship, and was a board member of the Community Law Center in Baltimore from 1988 to 2007.

From time to time since 1999, Warren has taught a seminar on criminal enforcement of environmental laws as an adjunct professor at the University of Maryland Law School and Georgetown Law Center.