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 of a criminal syndicate that illegally supplied alcohol—the forerunner of the Outfit—and was politically protected through the Unione Siciliana. A conflict with the North Side Gang was instrumental in Capone's rise and fall. Torrio went into retirement after North Side gunmen almost killed him, handing control to Capone. Capone expanded the bootlegging business through increasingly violent means, but his mutually profitable relationships with mayor William Hale Thompson and the city's police meant he seemed safe from law enforcement. Capone apparently reveled in attention, such as the cheers from spectators when he appeared at ball games. He made donations to various