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Sigal Mandelker is a member of Proskauer’s Litigation Department and White Collar Defense & Investigations Group. Leveraging her broad experience in senior government positions at the U.S. Department of Justice and the U.S. Department of Homeland Security, Sigal offers a nuanced understanding of domestic and international enforcement matters, crisis management, appellate litigation, compliance, and regulatory matters.

Sigal represents individual and corporate clients in connection with government investigations and crisis management, including in white collar criminal defense, False Claims Act investigations, Foreign Corrupt Practices Act (FCPA) investigations and compliance, anti-money laundering matters, Securities and Exchange Commission (SEC) enforcement matters, securities and shareholder derivative litigation, internal investigations, public corruption investigations, and cyber security matters. Her clients include major financial institutions, private investment funds, Boards of Directors and Audit Committees, ERISA funds, health care providers, and senior executives.

Sigal’s recent representations include:

  • Financial institutions and executives in connection with investigations by the Department of Justice, the SEC, and the Commodity Futures Trading Commission
  • Companies and individuals in connection with insider trading, ERISA fraud, public corruption, and other criminal allegations
  • Conducting internal investigations for public and private companies in connection with allegations of misconduct and crisis management
  • Advising companies on compliance matters

Before joining Proskauer, Sigal served in a number of senior Department of Justice and Department of Homeland Security positions following 9/11 and during other major crises. She played a significant role in managing sensitive national security, terrorism, and cyber-security matters, as well as in inter-agency crisis response and preparedness efforts.

Her government positions include serving as Deputy Assistant Attorney General in the Criminal Division of the Department of Justice from 2006 to 2009. In that capacity, she supervised four major prosecutorial sections: the Computer Crime and Intellectual Property Section, the Domestic Security Section, the Child Exploitation and Obscenity Section, and the Office of Special Investigations. She supervised a number of high-profile and complex domestic and international cross-border prosecutions, including some of the nation’s most significant cases. Sigal also led and participated in developing and implementing the strategy for various multi-agency and multi-national law enforcement programs, including relating to intellectual property enforcement, cyber security, human rights, alien smuggling, and human trafficking. In addition to testifying before Congress, she represented the U.S. government in various international fora, including before the United Nations.

From 2005 to 2006, Sigal served as Counselor to the Secretary of Homeland Security, where she assisted the Secretary in managing the Department’s national security and intelligence, immigration, and law enforcement agencies. She worked on a number of border security, emergency management, and law enforcement initiatives.

Sigal also served as Counsel to the Deputy Attorney General and as Special Assistant to the Assistant Attorney General for the Criminal Division, where she focused almost exclusively on counter-terrorism and national security in the aftermath of 9/11 during a period in which the nation was on high alert for follow-on attacks.

Sigal was also an Assistant United States Attorney in the Southern District of New York, a law clerk to U.S. Supreme Court Justice Clarence Thomas and U.S. Court of Appeals for the Fifth Circuit Judge Edith H. Jones, and Deputy Committee Liaison to U.S. House Majority Leader Richard Armey.