SHEILA ARMBRUST is a former federal prosecutor with extensive investigations and trial experience. Companies, boards, and individuals, often in moments of crisis, retain Sheila to assist them in conducting internal investigations and responding to investigative demands from the Department of Justice (DOJ), Securities and Exchange Commission (SEC), Federal Trade Commission (FTC), and state Attorneys General. Sheila also represents companies and individuals in high-stakes litigation in federal court. She counsels clients in the technology, artificial intelligence (AI), medical device, life sciences, and financial services sectors, and she advises companies on their compliance programs.
Sheila has been recognized by Chambers USA for her work in California Litigation: White-Collar Crime & Government Investigations (2024–2025).
Sheila rejoined Sidley after serving in trial-level and leadership positions in the U.S. Attorney’s Office for the Northern District of California. While at the U.S. Attorney’s office, she was a white collar prosecutor who led teams investigating and prosecuting crimes affecting the safe delivery of healthcare, including securities fraud, mail and wire fraud, violations of the Food, Drug, and Cosmetic Act, trade secret theft, trademark violations, computer fraud and abuse, money laundering, and drug trafficking.