November 4, 2025
Mr. Mendoza is a former federal prosecutor who represents individuals and businesses facing serious criminal exposure.
Before joining the firm, he worked at the U.S. Department of Justice as a Trial Attorney in the Tax Division and an Assistant United States Attorney in the Criminal Division of the Western District of Texas.Now in private practice, Mr. Mendoza handles sensitive internal investigations designed to assess criminal exposure before charges are filed and directs critical defense strategy in high-risk situations. That includes, for example, coordinating response efforts following execution of federal search warrants; crafting strategies for clients in receipt of a federal grand jury subpoena; and assisting clients who have been arrested out-of-state on federal charges. His practice spans criminal tax prosecutions (including payroll tax allegations, federal tax evasion, return-preparer fraud, and promotion of purported “tax shelters”); complex financial crime investigations (involving wire fraud, money laundering, PPP loan fraud, and other financial crimes); and high-dollar federal tax disputes, including federal refund litigation and “eggshell” IRS audits with serious criminal undertones.
While with the government, Mr. Mendoza led investigations and prosecutions involving a range of federal offenses, including fraud, tax crimes, large-scale narcotics trafficking, firearm offenses, crimes against children and persons, and smuggling matters. He advised federal agents on the strategic use of grand jury subpoenas, search warrants, and other investigative tools—helping shape charging decisions from the earliest stages of federal investigations. Mr. Mendoza additionally handled complex civil federal tax disputes. In 2024, the U.S. Department of Justice Tax Division awarded Mr. Mendoza a Special Commendation for his work in a complex injunction action involving nation-wide return-preparer fraud. Mr. Mendoza has handled numerous complex injunction actions and refund suits involving amounts up to $200 million in tax benefits sought.
Mr. Mendoza has appeared as counsel in more than 400 federal criminal cases, tried multiple federal criminal matters to verdict, and argued numerous dispositive and evidentiary motions. Several of his trial verdicts and motion rulings have been affirmed by the U.S. Court of Appeals for the Fifth Circuit, including by the court sitting en banc. In 2025, federal judges of the United States District Court for the Northern District of Texas appointed Mr. Mendoza to the Criminal Justice Act (CJA) Panel—a select group of judge-vetted trial lawyers appointed to represent defendants in certain federal criminal cases.
Mr. Mendoza began his legal career clerking for U.S. Magistrate Judge Renee H. Toliver and U.S. District Judge Marina Garcia Marmolejo. He is an honors graduate of St. Mary’s University School of Law, where he served as an editor of the St. Mary’s Law Journal.
Representative Experience
Federal Criminal Defense/Criminal Tax/White Collar Crime
- Representation of target under federal investigation for money laundering and wire fraud. Obtained decision from government that client is not a target.
- Representation of individual under return-preparer fraud investigation by Criminal Division of IRS. Obtained “closing letter” from IRS stating that it was no longer criminally investigating client.
- Representation of individual convicted of bank fraud in connection with post-conviction restitution. Obtained court order from federal judge in criminal case that reduced restitution by approximately 85%.
- Representation of individuals under federal investigations and prosecution for allegedly promoting tax shelters.
- Representation of individuals under investigation and prosecution for purported payroll tax crimes.
- Representation of individuals following execution of numerous federal search warrants in the Dallas area in connection with multi-agency federal investigation.
- Representation of individuals following execution of federal search warrants and the seizure of over $1million records in complex criminal tax investigation.
- Representation of individual under criminal indictment for allegedly committing bank and wire fraud in connection with purported PPP loans and falsified tax records.
- Representation of individual under indictment returned against more than 10 defendants accusing all defendants of conspiring to distribute a host of federal narcotics.
- Represented the United States in dozens of court hearings, including hearings on motions to suppress and to dismiss indictment, and at multiple trials before juries.
Federal Civil Tax
- Representation of individual in a multi-million-dollar tax refund suit arising from alleged carryback of losses in connection with jointly filed tax returns.
- Representation of business in connection with administrative tax refund claims arising from IRS’s misapplication of prior refunds, resulting in a multi-million-dollar overpayment.
- Representation of individuals under audit by the IRS.
- Representation of the United States in suit filed by plaintiffs challenging a statute in the Internal Revenue Code on First and Fifth Amendment grounds, raising political speech and other issues.
- Representation of the United States in multiple suits filed by fuel company seeking excise tax refunds of nearly $200 million based on fuel credits and excise tax imposed on crude oil and petroleum products.
- Representation of the United States in injunction and disgorgement action against national franchisor of tax preparation businesses and software, its owner, and a high-level franchisee, on grounds that all defendants engaged in fraud by trafficking IRS credentials, amongst other conduct, to generate $30 million.
- Representation of the United States in suit filed by cryptocurrency business and its owner alleging violations of the Right to Financial Privacy Act and seeking to quash IRS summonses, damages, and attorney’s fees.
- Representation of the United States in injunction action against a Nevada-based tax-preparation business and its owner who fabricated customers’ Schedule C business losses, Schedule A deductions, and various tax credits to reduce the customers’ tax due and inflate their tax refunds.
- Representation of the United States in enforcement action involving trust-fund-recovery penalties of $17 million and seeking to enforce tax liens on theories of fraudulent transfer and nominee liability.
- Representation of the United States in wrongful-levy suit filed in federal court alleging the IRS had discharged tax liens attached to a property later acquired by the plaintiffs.
- Representation of the United States in numerous summons-enforcement, collection, and tax lien-enforcement matters, including use of federal court-appointed receivers.
- St. Mary's University School of Law, J.D., cum laude, 2018
- St. Mary's Law Journal, Research/Articles Editor, Editorial Board Member
- Dean Charles Cantu Endowment Scholar
- Best Advocate, Hyden Mock Trial Competition, 2017
- Texas A&M International University, B.B.A., Management, 2014
- American Bar Association
- Criminal Justice Section
- Tax Section
- State Bar of Texas
- Tax Section
- Criminal Justice Section
- Dallas Bar Association
- Criminal Law Section
- Tax Section
- Dallas Association of Young Lawyers
- Dallas Hispanic Bar Association
- State Bar of Texas
- United States District Court – Northern District of Texas
- United States District Court – Southern District of Texas
- United States District Court – Eastern District of Texas
- United States District Court for the District of New Mexico
Experience
- Clerkships
- Law Clerk, U.S. Magistrate Judge Renee H. Toliver, N.D., Tex., Dallas, TX
- Law Clerk, U.S. District Judge Marina G. Marmolejo, S.D. Tex., Laredo, TX
- Internships
- United States Attorney's Office, Western District of Texas, San Antonio, TX
- U.S. District Judge David A. Ezra, Western District of Texas, San Antonio, TX
- Network Investigation Techniques: Government Hacking and the Need for Adjustment in the Third-Party Doctrine, 49 ST. MARY’S L.J. 237 (2018)
August 28, 2025
43rd Annual Tax Law in the Digital Age Course... [ read ]
May 23, 2025
A Sample of Tax Cases in Federal District Court: Criminal vs. Civil... [ read ]
Most federal tax disputes are resolved administratively or in the United States Tax Court, where taxpayers might challenge IRS determinations in a specialized forum that requires no prepayment of the disputed tax. But not all tax cases follow that path.
April 25, 2025
Pleading the Fifth in the Grand Jury Room... [ read ]
The Fifth Amendment to the United States Constitution provides that no person "shall be compelled in any criminal case to be a witness against himself." Popularized in courtroom dramas—"I plead the Fifth!"—this protection is widely understood at a surface level: it prohibits compelled self-incrimination. But depending on the case, its application may be increasingly nuanced and far from ubiquitous.
April 23, 2025
The Grand Jury Wants to Hear From You—Here's What That Means... [ read ]
For many professionals, the receipt of a federal grand jury subpoena may be the person's first encounter with the federal government. If you've received a federal grand jury subpoena, take a breath—but don't dismiss it. These subpoenas are not ordinary. Indeed, the service of a federal grand jury subpoena typically means the federal government—in many instances, the United States Department of Justice—is investigating a potential crime for which the recipient of the subpoena may have relevant information. Whether the federal government sees the recipient as a witness or a potential subject or target of that investigation, the recipient's response—or lack thereof—can significantly influence the government's next move.
