Resumen en Español
Mario Nguyen is a White Collar Criminal Defense and Investigations Attorney in Locke Lord’s Dallas office, led by a former U.S. Attorney for the Northern District of Texas. Mario 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, and conducting internal investigations on their behalf.
In addition to his devotion to 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 legal articles that are regularly published and cited by major publications, such as 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 who has spent over 200 hours in federal criminal trials 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 Dallas County Public Defender’s Office, where he was placed in the Capital Murder Division.
Mario’s training as a litigator harkens back to his education at 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 even 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.
Mario also helps clients navigate government investigations when they have been contacted by federal or state investigators, received a grand jury or administrative subpoena, or been raided by government agents.
Mario has assisted clients in navigating investigations involving various state and federal agencies and departments, 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; and Texas Alcoholic Beverage Commission (TABC).
Mario’s government investigations practice spans a range of issues, including the Foreign Corrupt Practices Act (FCPA), the False Claims Act (FCA), the Travel Act, the Sherman Act, the Clayton Act, the Racketeer Influenced and Corrupt Organizations Act (RICO), the Anti-Kickback Statute (AKS), the Stark Law, the Texas Patient Solicitation Act (TPSA), the Texas Free Enterprise and Antitrust Act (TFEAA), the Texas Medicaid Fraud Statute (TMFS), the Texas Business Organizations Code (TBOC), the Texas False Claims Acts (TFCA), healthcare fraud, conspiracy, false statement, obstruction, commercial bribery, money laundering, forfeiture, embezzlement, bank fraud, securities fraud, mail fraud, wire fraud, tax fraud, and public corruption.
In addition to his work as a litigator, Mario is a thorough and independent investigator. His investigations experience runs the gamut. Mario 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. Mario has also helped organizations uncover millions of dollars in fraud. Likewise, select branches of government have entrusted Mario, through Locke Lord’s White Collar Criminal Defense and Investigations Department, 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 regularly manages data preservation, collection, extraction, processing, analysis, review, and production for large datasets. Furthermore, because of his fluency in Spanish and international experience as a U.S. Fulbright Scholar, Mario is able to perform cross-border investigations with Latin American countries seamlessly.
- Represented surgeon in first-of-its-kind federal criminal case against allegations of healthcare bribes and kickbacks
- Conducted internal investigation into alleged misconduct on behalf of a branch of government
- Represented business consultant against allegations of multi-national government bribery scheme
- Conducted internal investigation for a global organization that resulted in uncovering multi-million 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
- 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 (Summer 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)
- 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)
Professional Affiliations and Recognitions
- President, Dallas LGBT Bar Association
- Dallas Association of Young Lawyers (DAYL) Leadership Class 2019
- 2016 Top 40 Latinxs Under 40 in Foreign Policy, Huffington Post
- 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