Mario Nguyen

Mario H. Nguyen




Resumen en Español

Mario Nguyen is an Associate in the White Collar Criminal Defense and Investigations Department of Locke Lord’s Dallas office, led by a former U.S. Attorney for the Northern District of Texas.  Mario is a skilled investigator and dedicated trial attorney, who has spent over 200 hours in federal criminal trials and conducted investigations with millions of dollars at stake.

He 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 authors legal articles that are regularly published and cited by major publications, such as the Wall Street Journal, The Texas Lawbook, 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.

Government Investigations

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 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.

Internal Investigations

In addition to his work as a litigator, Mario is a thorough and independent investigator. His investigations experience runs the gamut. Mario has 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.

Mario has interviewed countless witnesses — from C-suite executives, to accountants, and attorneys. Furthermore, because of his language abilities and international experience, Mario is able to perform cross-border investigations with Latin American countries seamlessly. He is also particularly skilled at maneuvering technology in investigations. Mario has experience in managing data preservation, collection, extraction, processing, review, and production.

Representative Experience

  • 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
  • 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

Professional History

  • 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 Chamber of Commerce (2011 – 2012)

Reported Decisions

  • 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
  • Member, LGBT Taskforce of the City of Dallas
  • 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