Seeger Weiss Welcomes Former Assistant U.S. Attorney Michael Castiglione as Firm Continues to Build Deep Bench of Talented Attorneys

Seeger Weiss is proud to announce that Michael Castiglione has joined the firm as Counsel, bringing nearly two decades of experience in in high-stakes litigation, government investigations, and complex civil matters.

Castiglione comes to Seeger Weiss following more than a decade as an Assistant United States Attorney (AUSA) in the Eastern District of New York, where he served in both the Civil and Criminal divisions. In the Civil Division, he served as lead counsel in United States v. UBS Securities, which resulted in a $1.435 billion settlement, the DOJ’s largest civil fraud recovery in 2023. Most recently, in the Criminal Division, he led grand jury investigations and prosecuted cases involving financial fraud, money laundering, tax offenses, and violent crime. He earned both the Attorney General’s Award for Fraud Prevention and the EOUSA Director’s Award for Superior Performance by a Litigative Team. Before entering public service, Castiglione practiced at Simpson Thacher & Bartlett LLP where he managed government investigations and litigated a broad range of state and federal matters, including securities, antitrust, and insurance coverage cases.

“Michael brings exactly the kind of depth, judgment, and courtroom experience that defines Seeger Weiss,” said Founding Partner Christopher A. Seeger. “His leadership in some of the most sophisticated fraud, forfeiture, and financial investigations in the country makes him a powerful addition to our team as we continue to expand the breadth of our complex, high-impact litigation.”

Castiglione’s arrival follows that of Daniel Marcet, also a former senior federal prosecutor, who joined the firm as Counsel in late December. The additions of Castiglione and Marcet reflect a focused effort by Seeger Weiss to add top-tier talent to plaintiff-side litigation.

Castiglione holds a J.D. from the University of Virginia School of Law, where he served on the editorial board of the Virginia Law Review, and a B.A. from Columbia College.

Learn more about Michael: https://www.seegerweiss.com/team/michael-castiglione/.

Prior results do not guarantee or predict a similar outcome in any future matter.