New York City police on Thursday were investigating the bold, fatal shooting of alleged Gambino crime boss Francesco “Franky Boy” Cali outside his Staten Island home.

Officers responding to a 911 call Wednesday night found Cali, 53, who was shot multiple times, police said in a statement. An emergency medical team rushed him to Staten Island University Hospital North, where Cali was pronounced dead.

"There are no arrests and the investigation is ongoing," police said in a statement.

Federal prosecutors have described Cali as a top leader of New York’s notorious Gambino crime family. His murder marked the most notable killing of a Gambino boss since 1985, when Paul Castellano was shot dead in front of the Sparks Steak House in Manhattan. Cali lived less than a half-mile away from Castellano’s Staten Island mansion.

John Alcorn, who teaches a course on the history of the Mafia at Trinity College in Connecticut, said the New York Mafia doesn't make news as it did 20 or 30 years ago, when John "Dapper Don" Gotti and others splashed across the headlines.

Technology, globalization and the rise of drug syndicates from around the world have trimmed the Mafia's impact, he said.

"Generally, they are in decline, but my hunch is that in some industries they can still have an impact by creating cartels that restrict competition among legitimate firms," Alcorn said.

Witnesses told the New York Post and other local media that Cali's killer fled the scene in a blue pickup.

“I’ve seen the (mob) movies," neighbor Prashant Ranyal, 39, told the Post. "But I’ve never seen any activity that we feel at all that there’s something strange about this area."

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Cali was a native of Sicily, and his wife is the niece of Gambino head John Gambino.

The New York Daily News and other media outlets in the city have reported that since 2015, Cali had ascended to the top spot in the gang, although he never faced a criminal charge making the claim.

Cali's 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 Gambino family was once among the most powerful criminal organizations in the United States, but federal prosecutions in the 1980s and 1990s sent its top leaders to prison and diminished its reach.

Iconic Gambino leader John Gotti died in federal prison in 2002. Gotti's brother, Gene, 71, was released from prison last year after serving almost 30 years for dealing heroin.

Another former leader of the group, Carmine John "The Snake" Persico Jr., died last week while serving a 139-year prison sentence. He was 85.

The names that were once commonly known are aging or dying, Alcorn said. He acknowledged that he no longer keeps up with the Mafia, having moved on to other research projects.

"Maybe the fact that so many scholars have moved on, that we don't hear about these guys anymore, shows that the Mafia has moved well past its prime," Alcorn said.

Contributing: The Associated Press