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Biography Press Room

Sigal Mandelker is a Partner in the New York office. She is a member of the firm’s White Collar Defense & Investigations, Appellate, International Practice, and Privacy Groups. Sigal represents individual and corporate clients in connection with government investigations and prosecutions, including white collar criminal defense, the FCPA, anti-money laundering matters, SEC and related enforcement matters, internal investigations, public corruption, and cyber security. She has a broad range of experience in domestic and international enforcement matters, appellate litigation, congressional investigations, immigration matters, and other legislative and regulatory matters.

Prior to joining Proskauer, Sigal served in a number of high-ranking positions at the Department of Justice and the Department of Homeland Security. From 2006 to 2009, Sigal was Deputy Assistant Attorney General in the Criminal Division of the Department of Justice, where she oversaw four major sections, including the Computer Crime and Intellectual Property and the Domestic Security Sections, and over 120 attorneys and other professional staff. In that capacity, she supervised a number of high-profile and complex domestic and international prosecutions, including some of the nation’s most significant cyber security and data breach cases, intellectual property, and border security cases, as well as crimes committed by contractors and former members of the military in Iraq. She also co-chaired a U.S.-China law enforcement intellectual property working group focused on enhancing cooperation and increasing the number of multinational intellectual property prosecutions. Additionally, Sigal helped establish a Southeast Asia Intellectual Property enforcement network. Further, she represented the Department internationally a number of times, including testifying before a United Nations Committee in Geneva and serving as the head of the U.S. delegation at the World Congress III against Exploitation of Children and Adolescents in Brazil.

Sigal testified before Congress a number of times on matters of criminal law, prepared Administration officials for congressional hearings, and negotiated various legislative provisions with congressional staff and within the Administration. She also represented the Department of Justice before the Federal Communications Commission, chaired Team Telecom, an interagency group that reviews telecommunications licenses where there is foreign investment and worked with a number of Federal agencies on a wide-range of regulatory and policy matters. In numerous enforcement areas, she coordinated the Department’s work with the FBI, DHS, ICE, U.S. Secret Service, the State Department, USTR, the Department of Commerce, the White House, the National Security Council, the Homeland Security Council and other government agencies.

In addition, Sigal previously served as an Assistant U.S. Attorney in the Southern District of New York, where she prosecuted cases involving health care fraud and money laundering, among many others, and as a Counsel to the U.S. Deputy Attorney General, where she focused on national security and terrorism matters. She began her prosecutorial career at the Department of Justice in the Criminal Division as a counsel to the Assistant Attorney General. Sigal also clerked on the United States Supreme Court for Associate Justice Clarence Thomas and on the United States Court of Appeals for the Fifth Circuit for Judge Edith H. Jones.

Sigal is a frequent speaker on cyber security and cross-border criminal investigations.