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
Al Capone after key witnesses recanted their statements. An indication of the attitude of local law enforcement to Capone's organization came in 1931 when Belcastro was wounded in a shooting; police suggested to skeptical journalists that Belcastro was an independent operator. The 1929 Saint Valentine's Day Massacre led to public disquiet about Thompson's alliance with Capone and was a factor in Anton J. Cermak winning the mayoral election on April 6, 1931. Capone was widely assumed to have been responsible for ordering the 1929 Saint Valentine's Day Massacre in an attempt to eliminate Bugs Moran, head of the North Side Gang. Moran