Cali's only mob-related criminal conviction came a decade ago, when he pleaded guilty in an extortion scheme involving a failed attempt to build a NASCAR track on Staten Island. He died in prison in 2002.
"The Gambino crime family during Castellano's reign was the largest criminal organization in the US, with law enforcement estimating it had some 250 "'made" members" and "more than 550 lower-ranking "associate' members".
Cali reportedly became the Gambino godfather in 2015 and is said to have brought a new crop of Italians to NY straight from Sicily.
Cali was the first NY crime family boss shot since 1985, when Paul Castellano, who owned a mansion on Todt Hill, was executed as he arrived at Sparks Steakhouse in Manhattan.
Police sources described Cali's murder as "disrespectful" because it happened right outside his family home.
The motive for the attack was under investigation, police said.
"There were like six shots, and then there were three more", one witness told the Daily News.
Federal prosecutors had referred to Cali in court filings in recent years as the underboss of the Gambino organization.
NY media reported that 53-year-old Cali was shot multiple times outside his vehicle on Staten Island on Wednesday evening, local time, by an unidentified man who then fled the scene in a blue auto.
Unlike the well-dressed Gotti of the late 1980s and early 1990s, Cali kept a low profile.
Paul Castellano, the Gambino family head at that time, was shot in the street on Manhattan's East Side.
The Gambino operation is said to be one of the five historic Italian-US mafia families in NY.
Last October, Bonanno crime family associate Sylvester Zottola, 71, was gunned down at a Bronx McDonald's drive-thru as he waited for a coffee.
Last week, the longtime boss of the Colombo crime family, 85-year-old Carmine "the Snake" Persico, died at a North Carolina hospital near the federal prison where he had been serving what was effectively a life sentence.
The day after Castellano's December 1985 murder, The New York Times called the Mob boss' death "highly stylized", but Giuliani dismissed such morbid romanticism.
"Papa! Papa!" one man yelled, a witness said.
Cali, who was born in Sicily, Italy, reportedly had strong ties to an Italian crime family.