New York, NY. Nixon Peabody LLP announced that Timothy D. Sini, a Government Investigations & White-Collar Defense partner and former federal prosecutor, will lead the AmLaw 100 firm’s Litigation Department and join its Management Committee, effective September 1.
Sini, who is also a member of Nixon Peabody’s Congressional Investigations and Crisis Management teams, has built a distinguished career in private practice and public service centered on white-collar matters and government investigations, civil litigation, outside counsel services, and crisis management for a portfolio of clients around the globe. Prior to joining the firm in 2022, Sini was the elected district attorney for Suffolk County, New York, and he previously served as an assistant US Attorney for the Southern District of New York and as commissioner of the Suffolk County Police Department.
“Through his deep leadership experience, Tim has earned a reputation as a trusted advisor to public and private sector leaders and also among his colleagues,” said Nixon Peabody CEO and Managing Partner Stephen D. Zubiago. “His commitment to serving clients, empowering our talent, and strategically recruiting top attorneys will serve our firm well as the Litigation Department continues to grow in size, scope, and strength at a time when our clients face highly complex challenges.”
Nixon Peabody’s nearly 400-member Litigation Department supports clients through all stages of litigation—from pre-trial to appellate proceedings—across a range of industries and jurisdictions. The department comprises the firm’s Complex Disputes, Construction and Real Estate Litigation, Privacy & Technology, Government Investigations & White-Collar Defense, Intellectual Property, and Labor & Employment practices.
Sini earned his JD from Brooklyn Law School, magna cum laude, and his BA from American University, also magna cum laude. He served as a law clerk to a federal district court judge in the Southern District of New York and a federal circuit court judge on the Second Circuit US Court of Appeals. In addition to being recommended in The Legal 500 United States 2026 for corporate investigations and white-collar criminal defense: advice to individuals, Tim has been recognized as an expert in investigations and prosecutions, testifying before the President’s Commission on Law Enforcement & the Administration of Justice; the US House of Representatives, Subcommittee on Counterterrorism and Intelligence; and the US Senate, Committee on the Department of Homeland Security and Government Affairs. He also received the Federal Bureau of Investigation National Executive Institute Certificate in Executive Leadership, Law Enforcement, and the Harvard University John F. Kennedy School of Government Leadership Decision Making Certificate, Executive Education.
Sini will succeed Anthony Barron as head of the Litigation Department. Department revenue grew in each of Barron’s five years in the role, with double-digit growth in the most recent two years, and attorney headcount rose by more than 20%. During his tenure leading the department, Barron oversaw the recruitment of high-profile former public sector leaders, including Sini, enhanced training to increase adoption of AI and other technology tools for litigation, and expanded the department’s risk advisory and dispute resolution capabilities to meet emerging client needs. When Sini’s new role takes effect, Barron will continue his active and nationally recognized construction litigation practice.
“It has been a privilege to have Tony on our management team throughout my tenure as the firm’s managing partner,” said Zubiago. “Our firm has benefited from Tony’s judgment, drive, and positive outlook, and we are tremendously thankful for his leadership.”
Among other recognitions, Barron has been highly ranked by Chambers USA in the field of Construction Law for a number of years and was named one of the top 250 lawyers in the country by Forbes: Meet America’s Top Lawyers 2025. He has served in several leadership roles throughout his nearly two decades with Nixon Peabody.
