Matthew R. Koerner
- Phoenix
- Washington, D.C.
Matt focuses on litigation, appeals, and investigations related to government actions, white-collar matters, and technology.
In both state and federal court and at both the trial and appellate levels, Matt Koerner has represented clients in matters involving technology platforms, cryptocurrencies and blockchain, internet and app data, elections, public policy, and asset forfeiture.
Through his government and white-collar practice, Matt commonly represents private and public parties in high-profile government-related disputes. He challenges and defends laws and governmental actions. He represents political parties, campaigns, and candidates in election-law and other litigation. And he defends individuals and entities in criminal cases and governmental investigations, including grand-jury proceedings, criminal sentencings, and investigations by the U.S. Department of Justice (DOJ) and the Arizona Attorney General’s Office.
In his appellate and litigation practice, Matt frequently tackles novel legal issues and appeals. He has briefed and argued cases before state and federal courts. His cases have been successfully decided based on federal and state constitutional law, statutory and contractual interpretation, administrative law, criminal law, property law, and more. And he has represented parties and amici curiae in matters before numerous appellate courts, including the Arizona Court of Appeals, the Arizona Supreme Court, and the U.S. courts of appeals.
Before joining the firm, Matt served as a judicial law clerk for a federal district judge and a court-of-appeals judge. In those roles, he assisted with cases before the U.S. Courts of Appeals for the Third, Eighth, Ninth, and Eleventh Circuits, as well as an original-jurisdiction matter before the Supreme Court of the United States. Before graduating from Duke University School of Law, Matt completed a full-time externship in Washington, D.C., at the DOJ, Criminal Division, Appellate Section. There, he assisted with cases before the Supreme Court and the courts of appeals.
Matt also maintains an active pro bono practice, including representing a group of pretrial detainees in a class action relating to conditions of confinement.
Education & Credentials
Education
- Duke University School of Law, J.D., Research Editor, Duke Law Journal, 2015
- Arizona State University, B.S. & B.A., 2011
Bar and Court Admissions
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Arizona
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District of Columbia
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Virginia
- U.S. Court of Appeals for the Ninth Circuit
- U.S. District Court for the District of Arizona
Clerkships
- Hon. Michael J. Melloy, U.S. Court of Appeals for the Eighth Circuit
- Hon. Rebecca Goodgame Ebinger, U.S. District Court for the Southern District of Iowa
Professional Recognition
Recognized by Best Lawyers: Ones to Watch, Criminal Defense: White-Collar Law, 2021-2024
Recognized by Best Lawyers: Ones to Watch, Appellate Practice, 2024
Recognized by Best Lawyers: Ones to Watch, Commercial Litigation, 2024
Insights
News
Professional Experience
Selected Governmental Litigation Experience
- Representing a political party and candidates in election-law and other litigation related to the 2024 elections.
- Defending the winning candidate for Arizona Attorney General in an election contest.
- Successfully represented a municipality in a constitutional challenge to several newly enacted statutes.
- Advised on legislative proposals, initiatives, referenda, and more.
Selected Appellate and Commercial Litigation Experience
- Successfully defended a municipality before the Arizona Supreme Court in an original-jurisdiction action brought by the Arizona Attorney General related to the municipality’s elections. State ex rel. Brnovich v. City of Tucson, 251 Ariz. 45, 484 P.3d 624 (2021).
- Successfully defended a municipality before the Arizona Supreme Court in an original-jurisdiction action brought by the Arizona Attorney General related to the municipality’s disposition of its own property. State ex rel. Brnovich v. City of Phoenix, 249 Ariz. 239, 468 P.3d 1200 (2020).
- Successfully represented a criminal defendant in a petition for review to the Arizona Supreme Court, which vacated the lower court’s adverse ruling. Reyes v. Cohen in & for Maricopa Cnty., 252 Ariz. 33 (App. 2021), vacated 2022 WL 4241984 (Ariz. Sept. 13, 2022).
- Represented amici curiae before the Arizona Supreme Court in a challenge to an Arizona governor’s executive order. Aguila v. Ducey, No. CV-20-0335, 2021 WL 1380612 (Ariz. Mar. 24, 2021).
- Successfully represented a plaintiff seeking to vacate the dismissal of his case based on forum non conveniens. Manoukian v. LaBianca, No. 1 CA-SA 20-0202, 2020 WL 6495071 (Ariz. Ct. App. 2020).
Selected White-Collar and Investigations Experience
- Defended major technology company in a consumer-fraud investigation by a state attorney general.
- Defended company in an investigation by the U.S. Securities and Exchange Commission.
- Defended energy company in an investigation by the U.S. Environmental Protection Agency and a U.S. Attorney’s Office.