Mack E. Jenkins is a partner at Hecker Fink LLP and leads the firm’s Los Angeles office.
Mack was previously the Chief of the Criminal Division of the United States Attorney’s Office (USAO) for the Central District of California, the largest such office in the country. While Criminal Chief, he supervised over 180 federal prosecutors and ten criminal prosecution sections in a district serving almost twenty million people. Mack, a highly accomplished trial lawyer, has litigated and tried some of the country’s most influential and high-profile cases. Mack was lead trial counsel in a series of federal trials stemming from his sprawling investigation into corruption within Los Angeles City Hall, each of which led to across-the-board convictions of high-level public officials, billionaire real estate developers, and multinational corporations. Mack’s landmark Los Angeles City Hall prosecution led to the district’s first ever federal racketeering convictions of a Los Angeles elected official (José Huizar), deputy mayor (Ray Chan), and City executive; 20 other defendants were convicted for corruption-related offenses.
Mack served as the lead prosecutor in the federal jury trial of a sitting U.S. Congressman charged with Federal Election Campaign Act (FECA) and Foreign Agents Registration Act (FARA) violations. The case also resulted in criminal resolutions against a former Presidential cabinet-level secretary and a foreign billionaire. Mack also successfully prosecuted former members of a California political dynasty (Ron and Tom Calderon) for bribery and money laundering after a multi-month wiretap investigation into the then state senator. He also oversaw another major multi-year corruption investigation into the nation’s largest utility, Los Angeles Department of Water and Power (LADWP), and the Los Angeles City Attorney’s Office related to a collusive lawsuit stemming from the LADWP overbilling scandal, which implicated high-ranking lawyers and top Los Angeles officials. Mack also supervised the successful investigation and trial of three-decade politician and former Chair of the Los Angeles County Board of Supervisors, Mark Ridley-Thomas, related to bribes he received from a prominent dean at the University of Southern California, and also charged a 72-defendant RICO case against the Broadway Gangster Crips, then the largest indictment in the district.
Mack has completed more than 17 federal jury trials, including six RICO trials, multiple VICAR murder cases, plus corruption, civil rights, continuing criminal enterprise, and obstruction matters. He has argued before the Ninth Circuit Court of Appeals over ten times and was the lead drafter in dozens of appellate briefs.
Prior to his term as Criminal Chief, Mack served as Chief of the Public Corruption and Civil Rights Section at the USAO for five years and was a federal prosecutor for almost 17 years. Mack has personally prosecuted hundreds of federal criminal cases and supervised hundreds more, including cybercrimes, corporate prosecutions, Foreign Corrupt Practices Act (FCPA), Office of Foreign Assets Control (OFAC)/sanctions, money laundering, cryptocurrency, kleptocracy, transnational organized crime, human trafficking, domestic terrorism, and national security/counterintelligence.
In private practice, Mack represents a diverse set of clients. Mack represents universities, non-profits, and state and local officials targeted by the federal government and in congressional inquiries. His extensive civil practice includes representing and advising hedge funds, along with relators and defendants in False Claims Act and qui tam cases. Mack also dedicates a significant part of his practice to public interest litigation.
Mack is a member of the American College of Trial Lawyers (ACTL). The ACTL is an invitation-only fellowship of exceptional trial lawyers of diverse professional backgrounds that is generally regarded as the country's preeminent trial organization. Membership is limited to 1% of the trial lawyers in each state.
Among other honors, Mack has twice received the Attorney General’s Award (the Department of Justice’s highest award), received the Executive Office for United States Attorneys (EOUSA) Director’s Award (the Department of Justice’s second highest honor), has thrice received the California Lawyer of the Year Award, along with being named the Federal Bar Association (FBA)’s Peter Mazza Top Federal Lawyer, and a Top 100 Lawyer by the Daily Journal. Mack is also a Fellow in the American Bar Foundation, a research institute committed to the principle that a deep understanding of the law is vital to a more just world. And Mack serves on the University of California–Irvine School of Law's Board of Visitors.
Prior to his almost two decades in public service, Mack worked in the Los Angeles office of a prominent international law firm where his practice focused on complex civil litigation, entertainment, white collar crime and government investigations. During that time, he was named Volunteer Attorney of the Year by Public Counsel for his successful class action litigation on behalf of a group of developmentally disabled foster children.
Mack is a graduate of Yale Law School and UCLA, where he completed his undergraduate studies and had a brief and inglorious stint as a walk-on for the UCLA football team.
Recent Representative Government and Internal Investigation Matters
- Represented State Bar of California in internal investigation stemming from issues and complaints relating to the February 2025 bar examination.
- Representing one of the nation’s largest law enforcement agencies in an internal investigation stemming from inquiries by its inspector general.
- Representing the City of Los Angeles, Ethics Commission, in matters occurring before Los Angeles Superior Court.
Recent Representative Higher Education Matters
- Representing universities in federal criminal investigations conducted by U.S. Attorney’s Offices, including successfully quashing federal grand jury subpoenas.
- Representing a university in an investigation conducted by the U.S. Department Health and Human Services’ Office for Civil Rights.
- Representing a university in investigations conducted by the U.S. Department of Education’s Office for Civil Rights.
- Representing multiple universities related to government inquiries regarding the provision of gender-affirming care.
Recent Representative White-Collar Matters
- Representing an international champion athlete in various Department of Justice (DOJ), Office of Foreign Assets Control (OFAC), Federal Bureau of Investigation (FBI), and Drug Enforcement Administration (DEA) cross-border investigations.
Recent Representative Commercial Matters
- Represented a California-based private investment firm in a multi-week arbitration stemming from an investor dispute raising novel broker/dealer and illegality issues and matters before the Securities and Exchange Commission (SEC).
Recent Representative Public Interest Matters
- Pedro Vasquez Perdomo et al. v. Kristi Noem, et al., 25-cv-05605-MEMF. Representing immigration advocacy groups alleging Fourth and Fifth Amendment violations against DHS/Immigration and Customs Enforcement (ICE) related to violent and abusive immigration enforcement in Los Angeles County.
- Gavin Newsom v. Donald J. Trump, et al., 25-cv-04870-CRB; CA No. 25-3727. Representing, before the district court and Ninth Circuit, amici, former secretaries of the U.S. Army and Navy and retired four-star admirals and generals, opining on Trump’s attempts to federalize the California National Guard for his policy goals. The Ninth Circuit affirmed the injunction against the federalization of the California National Guard, restoring control to Governor Newsom.
Recent Speaking Engagements
- Moderator, “Making the Executive Business Case for Compliance Excellence,” American Conference Institute — Global Anti-Corruption, Ethics & Compliance - New York, June 4, 2026
- Presenter, “Advanced Trial Skills in the Age of AI,” American Bar Association — White Collar Crime Institute, March 11, 2026
- Presenter, “Rule of Law, Executive Orders, and the Legal Profession,” Association of American Law Schools — Presidential Panel, January 5, 2026
- Presenter, “DOJ’s Shifting Priorities — An Analysis of the Bondi and Other Government Memos,” Women Lawyers Association, Beverly Hills Bar Association, May 29, 2025