Nguyen, Mario H.

Mario H. Nguyen


Mario Nguyen is a dedicated trial attorney, skilled investigator and legal scholar. He has spent over 200 hours in federal criminal trials, conducted investigations with millions of dollars at stake, published prominent criminal law articles and teaches white-collar criminal law as an adjunct law professor.

Mario Nguyen is a dedicated trial attorney, skilled investigator and legal scholar. He has spent over 200 hours in federal criminal trials, conducted investigations with millions of dollars at stake, published prominent criminal law articles and teaches white-collar criminal law as an adjunct law professor.

Mario represents individuals, public bodies and private companies by advocating for them in criminal proceedings and collateral civil matters, helping them navigate government investigations, conducting internal investigations on their behalf and assisting them build robust compliance programs.

In addition to his criminal pro bono work, Mario is passionate about developments in criminal law. He teaches White-Collar Criminal Law as an Adjunct Law Professor at Texas A&M University School of Law, and authors articles published and cited by the Wall Street Journal, The Texas Lawbook, JD Supra and Law360.

Criminal Defense & Complex Civil Litigation

As a former collegiate speech and debate national champion, Mario is a committed trial attorney with over 200 hours of federal criminal trial experience actively examining witnesses, presenting exhibits and arguing motions. He has managed discovery involving over two million documents, drafted complex court filings and defended depositions of named parties. In 2018, Mario also volunteered at the Capital Murder Division of the Dallas County Public Defender’s Office.

Mario’s litigation training harkens back to Harvard Law School, where he completed the Trial Advocacy Workshop and was one of 22 students in his class admitted to one of the school’s honor societies, The Harvard Legal Aid Bureau. There, concurrent to his legal education, Mario practiced family, housing, public benefits, special immigrant juvenile and wage and hour law for two years under Massachusetts Supreme Judicial Court Rule 3:03. Before graduating law school, Mario and his co-counsel secured the decision in CMJ Mgmt. Co. v. Wilkerson, 91 Mass. App. Ct. 276 (Mass. App. Ct. 2017), before the Massachusetts Court of Appeals, which set constitutional precedent in the Commonwealth.

Government Investigations

Mario also helps clients navigate government investigations, grand jury and administrative subpoenas, and search warrant raids by federal or state investigators, including the:

  • Department of Justice (DOJ)
  • Federal Bureau of Investigation (FBI)
  • U.S. Office of Personnel Management (OPM)
  • Department of Health and Human Services (DHHS)
  • Internal Revenue Service (IRS)
  • Department of Labor (DOL)
  • Securities and Exchange Commission (SEC)
  • Financial Industry Regulatory Authority (FINRA)
  • U.S. Department of Defense (DOD)
  • U.S. Postal Service (USPS)
  • Food and Drug Administration (FDA)
  • Drug Enforcement Agency (DEA)
  • Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF)
  • Federal Housing Administration (FHA)
  • Federal Trade Commission (FTC)
  • Defense Criminal Investigative Service (DCIS)
  • Office of Inspector General (OIG)
  • Texas Attorney General
  • Texas Alcoholic Beverage Commission (TABC)

Mario’s investigations practice spans a range of issues, including the:

  • Foreign Corrupt Practices Act (FCPA)
  • False Claims Act (FCA)
  • Travel Act
  • Sherman Act
  • Clayton Act
  • Racketeer Influenced and Corrupt Organizations Act (RICO)
  • Anti-Kickback Statute (AKS)
  • Stark Law
  • Texas Patient Solicitation Act (TPSA)
  • Texas Free Enterprise and Antitrust Act (TFEAA)
  • Texas Medicaid Fraud Statute (TMFS)
  • Texas Business Organizations Code (TBOC)
  • Texas False Claims Acts (TFCA)

Mario has additional experience in health care fraud, conspiracy, false statement, obstruction, commercial bribery, money laundering, forfeiture, embezzlement, bank fraud, securities fraud, mail fraud, wire fraud, tax fraud and public corruption.

Internal Investigations

Mario is also a thorough and independent internal investigator. He has interviewed countless witnesses — from C-suite executives, to accountants and attorneys. He has served as counsel to special litigation committees in shareholder derivative litigation and helped organizations uncover millions of dollars in fraud. Likewise, select branches of government have entrusted Mario to conduct internal investigations of government offices themselves.

As a Certified E-Discovery Specialist (CEDS), Mario is particularly adept at integrating technology into his investigations. He manages data preservation, collection, extraction, processing, analysis, review and production for large datasets. Additionally, his Spanish fluency and international experience as a U.S. Fulbright Scholar enable him to perform cross-border investigations with Latin American countries seamlessly.

Mario’s representative experience includes:

  • Represented surgeon in first-of-its-kind federal criminal case against allegations of health care bribes and kickbacks
  • Conducted internal investigation into alleged misconduct on behalf of a branch of government
  • Represented business consultant against allegations of multinational government bribery scheme
  • Conducted internal investigation for a global organization that resulted in uncovering multimillion-dollar fraud
  • Represented a dental provider against a state attorney general’s office regarding whistleblower (qui tam) allegations of Medicaid fraud
  • Conducted internal investigation on behalf of special litigation committee in shareholder derivative lawsuit
  • Represented real estate developer against criminal allegations of environmental pollution
  • Represented dealer-broker against alleged violations of administrative financial regulations
  • Conducted internal investigations on behalf of public school district into alleged employee misconduct
  • Represented alcoholic beverage distributor in inquiry by the Texas Alcoholic Beverage Commission (TABC)
  • Obtained diversion of felony criminal drug charge
Reported Decisions
  • Hurley v. Emigrant Bank, No. 3:19-CV-0011-B, 2019 WL 5537330 (N.D. Tex. Oct. 25, 2019)
  • United States v. Won, et al., No. 3:16-cr-516, 2018 WL 6840095 (N.D. Tex. Dec. 28, 2018)
  • Harvest Nat. Res., Inc. v. Garcia, et al., 2018 US Dist. Lexis 80315, 2018 WL 2183968 (S.D. Tex. May 11, 2018)
  • CMJ Mgmt. Co. v. Wilkerson, 91 Mass. App. Ct. 276 (Mass. App. Ct. 2017)
  • J.D., Harvard Law School, 2017
    S.J.C. Rule 3:03 Counsel, Harvard Legal Aid Bureau (2015–17)
    Stuntz Award for Compassion, Human Dignity, and Commitment to Justice
    Best Brief, Ames Moot Court Competition Semifinals
  • Non-terminal M.B.A. certificate, Technological Autonomous Institute of Mexico, 2013

    Fulbright Scholar to Mexico

  • B.A., Public Relations,

    magna cum laude

    , Western Kentucky University, 2012
    National Championship Speech and Debate Team
Bar Admissions
  • Texas
Court Admissions
  • U.S. District Court for the Eastern District of Texas
  • U.S. District Court for the Northern District of Texas
  • U.S. District Court for the Southern District of Texas
  • U.S. District Court for the Western District of Texas
  • Spanish
Professional Affiliations
    • President, Dallas LGBT Bar Association
    • Associate, Patrick E. Higginbotham Inn of Court (2020-2021)
    • Member, Leadership Class, Dallas Association of Young Lawyers (DAYL) (2019)
    • Member, National Association of Criminal Defense Lawyers
    • Member, Texas Criminal Defense Lawyers Association
    • Member, Dallas Hispanic Bar Association
    • Member, Dallas Asian American Bar Association
    • Member, Dallas Bar Association
    • Member, American Bar Association
Awards & Recognitions
    • Named, One to Watch, Dallas Association of Young Lawyers (2020)
    • Listed, Top 40 Latinxs Under 40 in Foreign Policy, Huffington Post (2016)
Professional History
    • Adjunct Law Professor, Texas A&M University School of Law (2019-Present)
    • Associate, Locke Lord LLP (2017-Present)
    • Member, National Diversity & Inclusion Committee, Locke Lord LLP (2017-Present)
    • Dallas Office Representative, Associate Committee, Locke Lord LLP (2018-Present)
    • Member, Technology Committee, Locke Lord LLP (2019-Present)
    • Summer Associate, Lieff, Cabraser, Heimann & Bernstein, LLP (2015)
    • Account Executive, Cultur8 (Omnicom) (2013-2014)
    • Venture Coordinator, Ashoka Social Entrepreneurs Mexico & Central America (2012-2013)
    • Economic Development Coordinator, Bowling Green Area Chamber of Commerce (2011-2012)