Capone joined Torrio in Chicago where he had become an influential lieutenant

[GoodTaste]

About 1920, at Torrio’s invitation, Capone joined Torrio in Chicago where he had become an influential lieutenant in the Colosimo mob. The rackets spawned by enactment of the Prohibition Amendment, illegal brewing, distilling and distribution of beer and liquor, were viewed as “growth industries.” Torrio, abetted by Al Capone, intended to take full advantage of opportunities.

Source: FBI

Does "he" refer to Torrio? Or Capone? Gramatically, it seems to be that Torrio became a lieutenant of the mob and invited Capone to join him for dirty business. I am not very sure.

 

[SoothingDave]

"He" is Torrio. Torrior had become a lieutenant in Colosimo's mob. Torrio invited Capone to come to Chicago.

The rule is that the pronoun attaches to the closest preceding noun.