Marisa S. West

MARISA WEST represents individuals and corporate clients in white collar criminal matters, internal investigations, congressional hearings, and government enforcement actions. Marisa has handled matters and investigations involving, among other things, the Foreign Corrupt Practices Act (FCPA), the False Claims Act, accounting fraud, tax fraud, healthcare fraud, and various securities laws and regulations.

As a former federal prosecutor, Marisa has extensive trial and investigative experience. Prior to joining Sidley, Marisa worked as an Assistant U.S. Attorney for the District of Columbia. In that role, she prosecuted local and federal crimes in the U.S. District Court for the District of Columbia and the District of Columbia Superior Court, bringing numerous cases to trial, preparing hundreds of witnesses to testify, and leading large investigatory teams. Marisa clerked on the U.S. District Court for the District of Columbia.

In her practice, Marisa provides anti-corruption compliance counseling, including designing and implementing global compliance programs, conducting compliance risk assessments, and advising clients on merger and acquisition transactions. Marisa has a robust immunities practice and thorough knowledge of the Bretton Woods Agreements Act, International Organizations Immunities Act, and the Foreign Sovereign Immunities Act. Marisa represents international organizations, including members of the World Bank Group, and foreign sovereigns in civil litigation matters across the country. In recognition of her practice, Marisa was named to Benchmark Litigation’s 2024 and 2025 “40 & Under List,” which spotlights top emerging talent in litigation in the United States.

• Assisted a telecommunications provider with an internal investigation in conjunction with a U.S. Federal Communications Commission (FCC) Office of Inspector General investigation concerning benefit program enrollments.
• Represented a publicly traded manufacturing company in connection with a DOJ investigation relating to alleged violations of the False Claims Act concerning the company’s contract with a defense contractor.
• Assisted an intelligence services company in connection with a DOJ False Claims Act investigation into historic conduct by the company’s predecessor related to work performed on government contracts.
• Represented a multinational pharmaceutical company in a Securities and Exchange Commission (SEC) FCPA investigation spanning Africa and Asia. Represented a former executive of a leading social media platform in testimony before the House Oversight and Accountability Committee.
• Represented one of the seven largest banks in the U.S. in relation to inquiries and oversight hearings by the House Financial Services Committee and Senate Banking Committee.
• Represented Human Rights Campaign and the Human Rights Campaign Foundation related to the inclusion of the organizations’ president, Alphonso David, in the New York Attorney General’s report of the investigation of Governor Andrew Cuomo.
• Represented Salesforce in its US$1.33 billion acquisition of Vlocity, Inc. (signed February 25, 2020).

Marisa’s pro bono practice includes successfully filing a writ of certiorari with the United States Supreme Court on behalf of an indigent pre-trial detainee.