Margaret M. Witherup

Michael J. Goldman is a top attorney recognized by Best Lawyers in the practice area(s) of Real Estate Law. Michael J., who practices law in Washington, District of Columbia, has been recognized since 2023. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Michael J. is held by other top lawyers in the same geographic and legal practice area.

Jeffrey N. Gibbs joined Hyman, Phelps & McNamara in 1990. Over the course of his career, he has developed an extensive knowledge of FDA law, from product approvals to advertising and promotion, and enforcement actions. In recent years, Mr. Gibbs has focused primarily on advising medical device and IVD companies, as well as pharmacies. Based on his extensive experience working with the industry on FDA issues, and previously for FDA, he provides efficient and insightful guidance. He has wor...

C. Sei-Hee Arii is a top attorney recognized by Best Lawyers in the practice area(s) of DUI / DWI Defense. C. Sei-Hee, who practices law in Rockville, Maryland, has been recognized since 2026. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which C. Sei-Hee is held by other top lawyers in the same geographic and legal practice area.

Kristen Klesh is a top attorney recognized by Best Lawyers in the practice area(s) of Advertising Law. Kristen, who practices law in Washington, District of Columbia, has been recognized since 2026. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Kristen is held by other top lawyers in the same geographic and legal practice area.

Michael K. Isenman is a top attorney recognized by Best Lawyers in the practice area(s) of Mutual Funds Law. Michael K., who practices law in Washington, District of Columbia, has been recognized since 2023. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Michael K. is held by other top lawyers in the same geographic and legal practice area.

Scott Simmer founded the Simmer Law Group in Washington D.C., in 2014, but he’s been practicing law for decades and is a seasoned expert at rooting out deceit and fraud in hidden corners of government programs, education, and healthcare industries. Joining with Baron & Budd in 2018 to form our Washington D.C. office, Mr. Simmer continues to represent whistleblowers bringing qui tam cases of fraud under federal and state False Claims Acts as well as IRS, Securities and Exchange Commi...

Adam Tarosky is a member of the Government Investigations & White Collar Defense practice group. He is a recent alumnus of one of the most powerful offices in the Department of Justice (DOJ). The Civil Fraud Section, the clearinghouse for all False Claims Act (FCA) activity in the country, annually coordinates the recovery of over $3 billion from health care providers, defense contractors, and other entities and individuals that do business with the federal government. Adam uses the knowl...

For more information, please visit www.gibsondunn.com/lawyer/debold-david/ .

Ian represents companies, executives, and fiduciaries in connection with Employee Retirement Income Security Act (ERISA) litigation, employee benefits and executive compensation matters, class actions, and other commercial disputes. Trained as a trial lawyer, Ian has focused almost exclusively on employee benefits related litigation for the past 15 years. What do you focus on? I focus my practice on ERISA litigation. With broad experience in this area, I help defend plans, fiduciaries, and co...

Louis Cohen is a senior counsel in the firm's Litigation/Controversy Department, and a member of the Appellate and Supreme Court Litigation Practice Group. He joined the firm in 1967. Mr. Cohen served as Deputy Solicitor General of the United States from 1986-1988, and focuses on US Supreme Court and other appellate litigation and corporations law. Mr. Cohen’s appellate practice has included more than fifty cases on the merits in the US Supreme Court and a large number of cases in the c...