Jack Goldsmith's new memoir 'In Hoffa's Shadow' centers on his investigation into his stepfather's involvement in the 1975 disappearance of mob-connected labor leader Jimmy Hoffa. Hoffa is portrayed by Al Pacino in Martin Scorsese's new film 'The Irishman.' Goldsmith is a Harvard Law professor, and best known for having headed the Office of Legal Counsel in the George W. Bush administration, where he challenged warrantless wiretapping and retracted memos legally justifying torture.