Michael Heitler began operating brothels in Chicago during the early 1900s based out of West Madison Avenue. By 1911 he had become a leading crime figure as a top liutenant to Chicago racketeer Jacob "Mont" Tennes, later driving rival Jack Zuta out of business with then ally Jake Guzik. Although arrested briefly for white slavery, Heitler continued to run independently of Jim Colosimo, and later Johnny Torrio, until the early 1920s after the formation of the Chicago Outfit.
Reluctantly joining Capone's organization, Heitler began informing Chicago police of criminal activities after rival Jake Guzik gained control of the organizations prostitution operations informing Judge John H. Lyle of extortion and other illegal activities in the Four Deuces nightclub. Heitler was soon found out by Capone after receiving a letter to the state's attorney office detailing Capone's prostitution operations and subsequently fired. Heitler continued to send information to police later claiming Capone's involvement in the death of Chicago Tribune reporter Jake Lingle which was received by Capone. Heitler may have also been involved in the conviction of Jack Guzik and Ralph Capone for tax evasion in 1930. Heitler, last seen with Capone associate Lawrence Mangano, was later found dead after a fire in his home on April 30, 1931.