Complex sentence: In 1932, Capone was convicted of tax evasion and sent to prison, leaving Frank Nitti ("The Enforcer") as boss of the Chicago Outfit and Ricca as underboss.
Split into simpler sentences: In 1932, Capone was convicted of tax evasion and sent to prison. Nominally, Frank Nitti ("The Enforcer") succeeded Capone as boss of the Chicago Outfit with Ricca as underboss.