Steven J. Tonsfeldt

Dan Barton has practiced criminal defense in the mid-peninsula since 1988. He received his A.B., magna cum laude, in 1983 from Brown University, where he was elected to Phi Beta Kappa and awarded the Prize for Academic Excellence in Latin American Studies. Mr. Barton received his J.D. from Stanford Law School in 1988, where his honors included induction into the Order of the Coif. Mr. Barton is a criminal law specialist certified by the California State Bar Board of Legal Specialization and a...

Patrick Hammon is a top attorney recognized by Best Lawyers in the practice area(s) of Commercial Litigation. Patrick, who practices law in Palo Alto, California, has been recognized since 2024. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Patrick is held by other top lawyers in the same geographic and legal practice area.

Rudy Kim is a partner in the Intellectual Property practice of Paul Hastings and is the Chair of the Litigation Department in Palo Alto. Mr. Kim has over 20 years of experience representing clients in high-stakes IP and technology-related litigation involving patent infringement, trade secret misappropriation, and complex commercial claims in federal district and appellate courts, in private arbitration, and before the U.S. International Trade Commission (ITC) and the U.S. Patent and Trademar...

Mark Selwyn is a partner in the Litigation/Controversy Department. He joined the firm in 1994. Mr. Selwyn’s practice focuses on intellectual property litigation. Major corporations have relied on him to litigate biomedical, electrical, chemical, mechanical, and business method patents involving a diverse array of technologies, including wireless communications, electronic commerce, digital cameras, solid state disk drives, location sensing, biosensors, water and wastewater filtration, i...

Lloyd Winawer is known for his work on complex business litigation and investigations. Lloyd focuses on disputes arising from mergers and acquisitions and other commercial transactions and securities law matters. Lloyd is the leader of Bergeson’s M&A Dispute Resolution Group. Lloyd has significant expertise in M&A disputes, having litigated and advised on numerous post-closing controversies related to earnouts, purchase price adjustments, contingent value rights, milestone and p...

Sonal N. Mehta is a trial lawyer representing many of the world’s leading technology and life sciences companies in high-stakes disputes. Ms. Mehta is regularly called upon by clients—ranging from Silicon Valley’s largest companies to cutting-edge startups—to serve as both lead counsel in the courtroom and trusted advisor in the boardroom. She has nearly 25 years of experience across all aspects of trial and appellate practice, including federal jury and bench trials, ...

Thomas J. Ivey is a top attorney recognized by Best Lawyers in the practice area(s) of Securities / Capital Markets Law. Thomas J., who practices law in Palo Alto, California, has been recognized since 2018. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Thomas J. is held by other top lawyers in the same geographic and legal practice area.

Dianne L. Sweeney is a top attorney recognized by Best Lawyers in the practice area(s) of Commercial Litigation. Dianne L., who practices law in Palo Alto, California, has been recognized since 2022. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Dianne L. is held by other top lawyers in the same geographic and legal practice area.

Ken D. Kumayama is a top attorney recognized by Best Lawyers in the practice area(s) of Litigation - Intellectual Property. Ken D., who practices law in Palo Alto, California, has been recognized since 2023. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Ken D. is held by other top lawyers in the same geographic and legal practice area.

Michael D. Celio is a top attorney recognized by Best Lawyers in the practice area(s) of Litigation - Securities. Michael D., who practices law in Palo Alto, California, has been recognized since 2023. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Michael D. is held by other top lawyers in the same geographic and legal practice area.