John Choon Yoo (; born July 10, 1967) is a Korean-born American legal scholar and former government official who serves as the Emanuel S. Heller Professor of Law at the University of California, Berkeley. Yoo became known for his legal opinions concerning executive power, warrantless wiretapping, and the Geneva Conventions while serving in the George W. Bush administration, during which he was the author of the controversial "Torture Memos" in the War on Terror. As the deputy assistant attorney general in the Office of Legal Counsel (OLC) of the Department of Justice, Yoo wrote the Torture Memos to determine the legal limits for the torture of detainees following the September 11 attacks. The legal guidance on interrogation authored by Yoo and his successors in the OLC were rescinded by President Barack Obama in 2009. Some individuals and groups called for the investigation and prosecution of Yoo under various anti-torture and anti-war crimes statutes. A report by the Justice Department's Office of Professional Responsibility stated that Yoo's justification of waterboarding and other "enhanced interrogation methods" constituted "intentional professional misconduct" and recommended that Yoo be referred to his state bar association for possible disciplinary proceedings. Senior Justice Department lawyer David Margolis overruled the report in 2010, saying that Yoo and Assistant Attorney General Jay Bybee—who authorized the memos—had exercised "poor judgment" but that the department lacked a clear standard to conclude misconduct. In 2020, Yoo advised Vice-President Mike Pence that he had no constitutional authority to interfere with the certification of the 2020 presidential election. Early life and education In 1967, Yoo was born in Seoul, South Korea. His parents were anti-communist, having been refugees during the Korean War. He immigrated to the United States with his family when he was a young child and grew up in Philadelphia. He attended high school at Episcopal Academy, graduating in 1985. Yoo matriculated at Harvard University where he majored in American history and was a member of The Harvard Crimson. In 1989, he graduated from Harvard with a bachelor's degree, summa cum laude. He then attended Yale Law School, where he was a member of the Yale Law Journal, graduating with a J.D. in 1992. Career Early legal service After law school, Yoo clerked for Judge Laurence H. Silberman of the U.S. Court of Appeals for the D.C. Circuit from 1992 to 1993 and for Justice Clarence Thomas of the U.S. Supreme Court from