O’Melveny Worldwide

O’Melveny’s White Collar Defense & Corporate Investigations Practice Highly Ranked in Chambers USA 2021

June 10, 2021

O’Melveny has once again been recognized as one of the nation’s leading law firms, earning top marks in the prestigious Chambers USA: America’s Leading Lawyers for Business 2021 guide.

The firm’s White Collar Defense & Investigations practice is featured in both East and West Coast regional rankings, including California, New York, and Washington, DC, and is ranked nationally for Corporate Crime & Investigations.

The practice was recognized for its “strengths in a range of criminal and investigatory proceedings,” its “impressive client base,” and its ability to “draw upon expertise in a number of global offices to advise clients involved in cross-border proceedings.” Chambers quoted clients who praised the practice for its “fantastic work in high-stakes situations,” and its focus on “providing the best possible practical and actionable advice."

Chambers USA 2021 also singled out seven O’Melveny lawyers for their outstanding work in the practice area across various regions.


Daniel Bookin is a highly experienced and distinguished white-collar criminal defense attorney who offers a wealth of knowledge in advising clients on internal investigations and regulatory proceedings.

“He's always been a leader in the white-collar practice, he's excellent.”

Steven Olson is a strong choice for clients on high-stakes internal and regulatory investigations, as well as offering clients an excellent pedigree in jury trial work.

Michael Tubach is widely considered a go-to practitioner for criminal antitrust matters, in which field he regularly advises on DOJ investigations.

"He is a great litigator both in court and in front of juries, he's just terrific."


Benjamin Singer is well regarded for his white-collar criminal defense practice. He is noted for his significant government experience, as well as his impressive client roster, which includes healthcare companies and government contractors. 

"He is a very smart, talented and tenacious lawyer."

"He has handled multiple, large-scale investigations, and has done so with finesse and an attention to detail that is particularly admirable."


Nicole Argentieri is recognized for her defense-side practice, and regularly undertakes a broad range of work including regulatory proceedings, enforcement actions and sensitive internal investigations.

"She understands the context of the client's business and is empathetic to what they need to achieve as a business person. She's also excellent at resolving issues with US regulators or the DOJ, and is a fantastic advocate in the courtroom."

"A terrific trial lawyer who advocates strongly for her clients."

"She has the full package, and can get into the most complex, difficult and sensitive issues."

Howard Heiss is a seasoned white-collar practitioner with expertise handling a broad range of criminal proceedings and investigations, including criminal trials.

"A very experienced and strong lawyer in the courtroom and boardrooms."

"He has the judgment and experience to make good tactical choices, knowing when to press and when to hold back."

"He has an excellent reputation with the government and very good judgment."

Mark Racanelli undertakes an array of criminal defense work, frequently advising on regulatory investigations and representing individuals at criminal trial.

"A great colleague with terrific insight into strategy and legal arguments."

"Strong in international matters and an effective advocate in front of the government."

"He is very smart and strategic."