Al Capone Mabel Walker Willebrandt recognized that mob figures publicly led lavish lifestyles yet never filed tax returns, and thus could be convicted of tax evasion without requiring hard evidence to get testimony about their other crimes. She tested this approach by prosecuting a South Carolina bootlegger. In 1927, the Supreme Court ruled in "United States v. Sullivan" that illegally earned income was subject to income tax; Justice Oliver Wendell Holmes Jr. rejected the argument that the Fifth Amendment protected criminals from reporting illegal income. The IRS special investigation unit chose Frank J. Wilson to investigate Capone, with the focus on his
Al Capone along and refused to allow Capone to plead guilty for a reduced sentence. On the second day of the trial, Judge Wilkerson overruled objections that a lawyer could not confess for his client, saying that anyone making a statement to the government did so at his own risk. Wilkerson deemed that the 1930 letter to federal authorities could be admitted into evidence from a lawyer acting for Capone. Much was later made of other evidence, such as witnesses and ledgers, but these strongly implied Capone's control rather than stating it. The ledgers were inadmissible on grounds of statute of limitations,