Rebecca Mermelstein is a first-chair trial lawyer with extensive experience handling white collar and finance-related investigations and litigation. She advises corporate and individual clients on complex white collar matters, including regulatory actions, internal investigations, and compliance initiatives.
Prior to joining O’Melveny, Rebecca spent more than a decade as an Assistant U.S. Attorney in the U.S. Attorney’s Office for the Southern District of New York. She was a senior member of the Securities and Commodities Task Force before rising to Co-Chief of the General Crimes Unit. Rebecca has tried 12 cases to verdict, briefed and argued numerous federal appeals, and conducted or supervised more than 1,000 investigations, including grand jury investigations and cross-border matters involving simultaneous investigations by multiple U.S. and international regulators. Her expertise spans securities and accounting fraud, insider trading, Ponzi schemes, money laundering, cybercrime, public corruption, human trafficking, and sexual misconduct.
Through her work leading investigations and prosecutions, Rebecca has established strong working relationships with U.S. Attorney’s Office colleagues and officials at the Securities and Exchange Commission, Commodity Futures Trading Commission, and the Public Company Accounting Oversight Board, as well as federal law enforcement agencies. The knowledge she has gained from her experience and relationships helps her achieve the best possible results for clients.
As a former senior advisor to the US Commerce Secretary and executive director of SelectUSA, Steve also advises non-US headquartered companies on investing and operating in the US and navigating the regulatory, political, and litigation environment, including advising PRC-based clients.
In 2021, Steve served as interim general counsel and chief legal officer for Hyundai and Genesis Motor Americas. He is chair of the World Trade Center Los Angeles and past chair of the Los Angeles Economic Development Corporation. He also serves on the board of the Public Policy Institute of California and the Rose Bowl Legacy Foundation, and is a trustee of Pomona College.
Steve has been recognized by Chambers USA, The Legal 500 US, and Benchmark Litigation as a leading lawyer in the area of White Collar Criminal Defense. In recent editions of Chambers USA, clients describe Steve as “very adept at anticipating legal issues—quickly cutting through complex facts to distill key issues” and as someone with “great integrity” who is “always working to protect his client.” Clients also note that Steve “has excellent judgment, is very commercial, anticipates risk and is pragmatic,” is “completely committed to his clients” and “a top-flight investigations and trial attorney.” Sources also tell Chambers that Steve “is very results-oriented, and delivers with extraordinary speed,” “has a very, very good touch in terms of negotiations,” and “can make on-the-spot calls which inevitably turn out to be right and he has a sixth sense when it comes to governmental agencies.” Steve has also repeatedly been recognized as among the “Top White Collar Lawyers” by the Daily Journal and among the “Most Influential People in Los Angeles” by The Los Angeles Business Journal.
- Represent a global commodities trading company in a wide-ranging FCPA investigation by the United States Attorney’s Office for the Eastern District of New York and Main Justice involving alleged conduct in South America.
- Represent a Fortune 50 company in a DOJ investigation under the False Claims Act.
- Represented an entertainment company in an internal investigation of senior officers concerning possible violations of internal finance and approval policies.
- Represented a global consulting firm in an internal investigation and litigation relating to allegations under the Adult Survivors Act.
- Secured an acquittal for a Louisiana man who served more than eight years in prison after he was wrongfully convicted of second-degree murder by a non-unanimous jury.
Government Experience
- Supervised dozens of jury trials and more than 1,000 cases involving securities fraud, wire fraud, mail fraud, tax fraud, money laundering, access device fraud, cybercrime, immigration offenses, child exploitation, human trafficking, robbery, narcotics trafficking, and firearms offenses.
- Investigated and prosecuted complex financial crimes, including accounting fraud, insider trading, market manipulation, investment adviser fraud, wire fraud, bank fraud, insurance fraud, and money laundering. Managed relationships with FBI and SEC, among other agencies.
- Conducted 12 criminal trials, including numerous multi-defendant white-collar cases. Briefed and/or argued more than a dozen appeals in the Second Circuit.
- Investigated, prosecuted, and supervised numerous sex-crimes cases, including leading the investigation and prosecution of a 19-defendant international sex-trafficking ring and supervising multiple cases of sex abuse by middle school and high school teachers.
Admissions
Bar Admissions
- New York
- New Jersey
Court Admissions
- United States District Court, Southern District of New York
- Second Circuit Court of Appeals
Education
- Harvard Law School J.D., 2005: cum laude
- Columbia College, B.A., Comparative Religion, 2001: magna cum laude; Phi Beta Kappa
Honors & Awards
- Recognized by Chambers USA for White-Collar Crime & Government Investigations (2026)
- Recognized as “Up and Coming” by Chambers USA for Litigation: White-Collar Crime & Government Investigations (2025)
- Recommended by The Legal 500 US for Corporate Investigations and White-Collar Criminal Defense (2024)
Professional Activities
Publications
- "Turning the Tables on DOJ: Individual Defendants Wield Corporate Criminal Enforcement Policies Against the Government," New York Law Journal (Mar. 6, 2023)
Clerkship
- Honorable Charles P. Sifton, Eastern District of New York
Corporate & Government Experience
- Senior Advisor to the Secretary of Commerce, and Executive Director of SelectUSA, US Department of Commerce (2011-2013)
- Assistant United States Attorney, United States Attorney's Office for the Central District of California (1999-2004)