Derek A. Hahn, Partner Orange CountyLos Angeles
Phone: +1 949.263.8400
3 Park Plaza, 20th Floor
Irvine, CA 92614-8505
Phone: +1 213.622.4750
515 South Flower St., 40th Floor
Los Angeles, CA 90071-2201

Derek Hahn is a partner in Crowell & Moring's Orange County and Los Angeles offices. His practice focuses on white collar defense, internal investigations, complex litigation, and compliance counseling.

Mr. Hahn assists companies and individuals in the defense of government investigations and enforcement actions across a wide range of industries. He has represented clients in an array of white collar matters, including financial fraud, public corruption, conflicts of interest, insurance fraud, counterfeiting, procurement integrity, and health care fraud. He has also defended clients in several multi-million dollar environmental enforcement matters at both the federal and state level.

Mr. Hahn has substantial expertise in matters involving the Foreign Corrupt Practices Act (FCPA). He has counseled clients on FCPA matters across six continents, including government and internal investigations, third-party due diligence reviews, compliance program and training evaluations, and post-acquisition anti-corruption risk assessments. Mr. Hahn has defended multiple FCPA investigations by the Department of Justice (DOJ) and the Securities and Exchange Commission (SEC).

Selected Engagements

  • Represented multinational company and individuals in multiple investigations by the DOJ and SEC of potential FCPA violations.
  • Assisted defense of former president and CFO of pharmaceutical company during internal investigation of FCPA issues by independent Board committee.  
  • Defended privately-held business in investigation by an Assistant U.S. Attorney into the alleged sale of counterfeit grey market goods.
  • Represented health care executive in connection with federal health care fraud and public corruption investigations.
  • Defended the nation's largest cement manufacturer in multistate Clean Air Act investigations and federal court litigation by the DOJ Environmental Enforcement Division and Environmental Protection Agency (United States v. CEMEX California Cement, LLC, ED-CV-07-00223-GW (C.D. Cal. 2009); United States v. CEMEX, Inc., No. 1-09-CV-00019-MSK (D. Colo.)).
  • Represented former CFO of publicly-traded pharmaceutical company in connection with accounting fraud investigation.
  • Advised multi-billion dollar public retirement fund on conflicts of interest under California Government Code Section 1090.
  • Represented oil company and oil company executives in connection with criminal environmental litigation.
  • Defended IT contractor in a federal grand jury investigation predicated on whistleblower allegations of mischarging and revolving door violations related to a multi-million dollar Iraq reconstruction contract.
  • Represented client in discharge investigation by the California State Water Resource Control Board's Office of Enforcement.

Mr. Hahn regularly volunteers time to pro bono matters as part of his practice. Recently, he co-chaired a pro bono jury trial in a federal civil rights case. He also assists low income individuals in obtaining free legal representation through the Archdiocesan Legal Network. Mr. Hahn previously served on the Board of the Orange County Chapter of the National Contract Management Association. He was elected president for two consecutive terms and led the Chapter to earn the organization’s highest national recognition during his tenure.

Mr. Hahn graduated cum laude from Duke University with a B.S.E. in civil and environmental engineering. He received his J.D. from the University of Virginia School of Law, where he was a member of the Virginia Law Review.


Admitted to practice: California

American Bar Association, Cyber Crime Committee and Southern California White Collar Crime Committee
Past-President, National Contract Management Association, Orange County Chapter
Environmental Law Institute
Association of Surfing Lawyers

Highlights, News & Knowledge

Speeches & Presentations


  • "The Evolving Landscape of Legal Privilege in Internal Investigations," Criminal Justice, Vol. 30, No. 2, American Bar Association (Summer 2015). Authors: Janet Levine, Gail D. Zirkelbach, Derek A. Hahn, and Danielle Rowan.
  • "Drawing the Battle Lines: Recent Challenges to Privilege and Lessons Learned," National Institute on White Collar Crime, New Orleans, LA (March 2015). Authors: Janet Levine, Gail Zirkelbach, Derek Hahn, and Danielle Rowan.

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Firm News & Announcements

Jan.09.2017 Crowell & Moring Elects Six New Partners and Promotes 19 Associates to Counsel
Oct.12.2015 Crowell & Moring Recognized Among Global Investigation Review's 'GIR 100'
Feb.16.2012 Crowell & Moring Among Law360's Elite "Practice Group of the Year" Listing for Government Contracts and White Collar
Jan.26.2012 Crowell & Moring Elects Seven New Partners and Promotes 22 Attorneys to Counsel Positions