The reputed head of New York’s notorious Gambino crime family has been shot dead on Staten Island in the first targeted killing of a mob boss in the city in more than 30 years.

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 9pm on Wednesday evening. Cali was taken to hospital where he was pronounced dead. There have been no arrests.

On Thursday morning, the New York police department had sealed off the residential block where the killing happened. The shooting is estimated to have happened between 9pm and 10pm on Wednesday night. Neighbors were jittery about disclosing their full identities to the public when talking to reporters about what they had witnessed and Staten Island’s mafia legacy.

“Yesterday was crazy,” a man who was only prepared to disclose his name as Thomas, told the Guardian. He said he was watching television in his house, around 9.40pm, when he heard gunshots ring out. “I heard five, six or seven gunshots,” he said.

“Nobody was expecting that, because it’s a safe neighborhood,” he added.

Despite the shocking incident, Thomas was not entirely surprised.

“There’s so many mob members out here. They ain’t gonna talk to you … They’ve been here for over 40 years, before I was even born. So it’s nothing we can change. It’s been happening for so long,” he said.

Behind the yellow crime-scene tape, Cali’s home could be clearly seen, a two-storey red brick house with a built-in, two-car garage, sitting at a curve in the road.

Cali’s wife and children were reportedly home at the time of the attack.

It appeared to be a well-to-do street with many large homes set behind gates or high walls, in the largely residential borough of Staten Island, a short ferry ride from the tip of the island of Manhattan.

Investigators said on Thursday that they were still searching for the gun used in the murder and the blue pickup truck that a 911 caller claimed ran over Cali. Officers could be seen combing through bushes in neighboring homes.

Federal prosecutors in Brooklyn had previously 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.

An image of Francesco Cali handed out by Italian police in 2008. Photograph: AFP/Getty Images

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.

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 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 Steak House in Manhattan in 1985.

On Staten Island, Todt Hill is known for its mafia history. Castellano owned a home on Benedict Road. A home on nearby Longfellow Road served as the filming location of the Corleone compound in The Godfather.

The Gambino family was once among the most powerful criminal organisations in the US, but federal prosecutions in the 1980s and 1990s sent its top leaders to prison and diminished its reach.

At that time, one of the most infamous godfathers in US mob history, John J Gotti, was the head of the family, having succeeded Paul Castellano, whose murder he had ordered. Gotti was convicted of racketeering and murder in 1992. He died of cancer in 2002. In 2013 his son, the former Gambino boss John A Gotti, was stabbed in the stomach in Syosset, New York. He survived.

While decades have passed since the last suspected assassination of a mob boss in New York, lower-level members have been targeted for violence much more recently. In October, Sylvester Zottola, a suspected associate of the Bonanno crime family was shot and killed at the drive-through window of a Bronx McDonald’s restaurant.

Three months earlier, Zottola’s son Salvatore was shot multiple times by a gunman at the Zottola family’s Bronx compound. He survived.

Staten Island is large in surface area and has a population of almost half a million, but is traditionally the most overlooked of New York City’s five boroughs. Its residents are disproportionately white, Italian and Irish American, and its suburban-style neighbourhoods are packed with the homes of the city’s police and firefighters.

Unlike the solidly Democratic-leaning rest of the city, Staten Island has been traditionally Republican and gave Donald Trump a hero’s welcome there on the 2016 campaign trail, before he won the borough.

But the Democrat Max Rose beat the congressional Republican incumbent last November in a shock flip to win a seat in the House of Representatives.

The Associated Press contributed to this report.