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
Polish-American organized crime Polish-American organized crime Polish-American organized crime has existed in the United States throughout the 20th and 21st centuries. Although not as well known as Italian, Irish, Russian or Jewish mafias, the Polish mob has a presence in many urban Polish American communities. During Prohibition, many Polish-American criminal gangs took advantage of the opportunity to make money through the illegal sale of alcohol. In Chicago, Joseph Saltis and Jake Guzik allied themselves with Al Capone's Chicago Outfit. However, fighting Capone was the North Side Gang, which, while mostly Irish-American, had a large Polish presence as well, with leaders Bugs Moran (disputed)