Capone spent his early years near his home on the docks of the Brooklyn Navy Yard. He was a good student in his youth, but when he was 14, he struck a teacher in the face while attending P.S. 133. According to some sources, Capone was expelled, while others claim he left school on his own. In any event, he never returned. ¹⁾

Capone went to work after graduating from high school, working at a candy store, a bowling alley, and a local bindery. ²⁾

With his brother Ralph, he was a player of a semi-pro Brooklyn baseball team. ³⁾

At the same time as he worked respectable employment, Capone was a member of street gangs that specialized in minor crime and destruction. In addition to the South Brooklyn Rippers and Junior Forty Thieves, Capone joined Johnny Torrio's James Street Boys gang, where he became Torrio's protégé; and at 16, Capone joined the Five Point Gang, named after the notorious 19th-century Manhattan slum.⁴⁾

Capone allegedly insulted the sister of a local petty offender called Frank Galluccio, who then cut him across the face three times with a pocket knife. Two men approached “Alfonzo Capone” and cut his cheek with a knife.⁵⁾

Dean O'Banion, the leader of the Irish North Side Gang, was assassinated outside his florist shop on Torrio's orders in November 1924. That gang reacted the following year, attempting to assassinate Torrio in a gunfight. Torrio was wounded but lived; after some time in prison, he resigned, handing over control of the Chicago-based criminal organization to the 26-year-old Capone.⁶⁾