Cali was fatally shot multiple times in the Todt Hill area shortly after 9pm on Wednesday, according to the New York Police Department.
“Upon arrival, officers found a 53-year-old male with multiple gunshot wounds to the torso,” said the department. “EMS also responded to the scene and transported the victim to Staten Island University North, where he was pronounced deceased.”
US media outlets, citing police sources, reported that he was shot at least six or seven times and the gunman sped off in a blue pickup truck.
Cali was “a real quiet old-school boss,” a source told the New York Post.
The Gambino crime operation is widely believed to be one of the five historic Italian-American mafia families in New York.
Charges against Gambino family operatives have included murder and racketeering, according to The New York Times.
Federal prosecutors in Brooklyn had referred to Cali in court filings in recent years as the underboss of the Gambino organisation, related through marriage to the Inzerillo clan in the Sicilian Mafia.
Multiple accounts in the press since 2015 claimed Cali had become the boss of the organisation, but he did not face any criminal charge describing him as its leader.
Cali was sentenced to 16 months in federal prison and was released in 2009 after he pleaded guilty to an extortion conspiracy involving a failed attempt to build a Nascar track on Staten Island.
There is no known motive for the shooting of Cali, a police watch commander said. “There are no arrests and the investigation is ongoing,” police said in a statement.
The last reputed crime family boss to be shot in New York City was Paul Castellano. He was assassinated outside Sparks Steakhouse in Manhattan in 1985.
Additional reporting by agencies