Francesco "Franky Boy" Cali, 53, was found with multiple gunshot wounds to his body at his home in the borough's Todt Hill section just after 9 p.m.
[Ads /]
Cali was taken to a hospital where he was pronounced dead. There have been no arrests.
No other information was provided by police.
Federal prosecutors in Brooklyn had referred to Cali in court filings in recent years as the underboss of the Gambino organization, related through marriage to the Inzerillo clan in the Sicilian Mafia.
Multiple press accounts since 2015 said Cali had ascended to the top spot in the gang, although he never faced a criminal charge saying so.
[Ads /]
His only mob-related criminal conviction came a decade ago, when Cali pleaded guilty in an extortion conspiracy involving a failed attempt to build a NASCAR track on Staten Island. He was sentenced to 16 months in federal prison and was released in 2009.
The last crime family boss to be shot in New York City was Paul Castellano. The Gambino crime boss was assassinated outside Sparks Steakhouse in Manhattan in 1985.
The Gambino Family was once among the most powerful criminal organizations in the U.S., but federal prosecutions in the 1980s and 1990s sent its top leaders to prison and diminished its reach.