Zachary Hafer

Zachary Hafer is a Partner in the Government and Internal Investigations Practice in the firm’s Boston office. A former federal prosecutor and prominent trial lawyer, he represents companies, boards and individuals in highly complex and sensitive internal and government investigations, including matters related to the Anti-Kickback Statute, FCA, FCPA, the CARES Act and related SEC matters, among others. Prior to joining private practice, Zach served with the U.S. Attorney’s Office for the District of Massachusetts for 14 years, including as Chief of the Criminal Division, where he supervised approximately 100 federal prosecutors and managed the investigation and prosecution of some of the nation’s most important federal criminal cases.

Practicing since 2003; joined Simpson Thacher as a partner in 2025. Prior to joining Simpson Thacher, Zach was a partner at another international law firm.

University of Virginia School of Law, 2003 J.D.; Dartmouth College, 1999 B.A. cum laude