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 "Big Jim" Colosimo as an enforcer. Capone began in Chicago as a bouncer in a brothel, where he contracted syphilis. Timely use of Salvarsan probably could have cured the infection, but he apparently never sought treatment. In 1923, he purchased a small house at 7244 South Prairie Avenue in the Park Manor neighborhood on the city's south side for . In the early years of the decade, his name began appearing in newspaper sports pages where he was described as a boxing promoter. Torrio took over Colosimo's crime empire after Colosimo's murder on May 11, 1920, in which Capone was