(CNN) Cigar-chomping Mafia bosses in dapper suits once dominated perceptions of organized crime in the United States. While the dons are less flamboyant now and shun the spotlight, their work continues in the shadows, experts say.

The killing of Gambino family boss Frank Cali brought back memories of mobsters getting whacked in brazen hits that stunned the nation decades ago. Cali was found gunned down Wednesday night outside his home in New York, leading to initial speculation on whether the killing was related to a Mafia feud.

The last time a Mafia boss was assassinated in the city was 34 years ago, when former Gambino don Paul Castellano was shot dead as he arrived at a popular steakhouse in midtown Manhattan, a hit ordered by the so-called "Dapper Don" himself, John J. Gotti.

CNN legal analyst James Gagliano said Cali's killing reminded him of his work with the FBI's Gambino crime squad in New York City in the 1990s.

"Scenes like this were somewhat commonplace during the mob wars," he tweeted. "Guarantee this does not go unanswered. Hoping this isn't the opening salvo, ushering in a new era of mob violence."

Mafia groups have reinvented themselves

Executing Mafia dons may not be as common today, but organized crime is still big business.

Just ask drug kingpin Joaquin "El Chapo" Guzman or those in the Mexican and Colombian drug cartels, which have largely overtaken the spotlight from the American Mafia.

Even without the spotlight, American mobsters have evolved with the times and remain influential in their own cities and regions, experts say.

In New York, for example, the FBI says the same five major families of the Italian-American Mafia dominate organized crime: Bonnano, Columbo, Gambino, Genovese and Lucchese.

In the post-Godfather era, Mafia groups have broken down their traditional structures and reinvented themselves to survive in the new world of transnational organized crime, said David Shapiro, a professor at the John Jay College of Criminal Justice at the City University of New York.

Their new structure means the walls among the five families are less rigid and they have more interactions with other groups, he said.

Under traditional Mafia structures, the boss or the don is the leader and the underboss is the second in command -- usually, a son groomed to take over the family business. The No. 3 person is an adviser and confidant, and below him, a capo who leads the lowest members of the crime family, known as soldiers.

An associate is part of the crew, but performs crimes under the protection of members and gives his share of illegal proceeds to a supervisor.

Drug cartels have changed the landscape

The cartels' global dominance has changed the way Mafia groups operate, experts say.

The days of colluding with labor unions to skim money from contracts are all but gone, Shapiro said.

But mobsters in New York and other American cities still rely on some of the same racketeering scams they always have: selling drugs, and trafficking firearms, humans and counterfeit goods. They also dabble in credit card scams, money laundering, internet fraud and other racketeering scams made easier in the digital age, he said.

"Now, you have the gig economy in organized crime," he said. "You have fluid networks, you don't have the same firewalls between the Gambinos and Lucchese groups."

In that sense, not much has changed. Organized crime is often described as a business like any other, just illegal. It has long existed in various formats, from localized rackets to global enterprises, operated by groups that interact with each other when it's in their best interest and compete with each other when it's not, said Dennis Kenney, professor of criminal justice at John Jay.

What's different now, he added, is the playing field is bigger and more crowded, meaning more opportunities to reap illicit profits.

"The economy is bigger now, there's more to be had, the pie is bigger," Kenney said.

Mob boss Carlo Gambino smiles while standing in handcuffs after being arrested by the FBI.

Disputes are mainly resolved by violence

With competition comes a struggle for dominance.

While the Gambino and Lucchese families remain strong and active, the Columbo and Bonannos families have shrunk over the years, said Geoff Schumacher of the Mob Museum in Las Vegas.

America's changing demographics are bringing new organized crime groups into major cities, Schumacher said. Turf battles are not just Gambino against the Genovese anymore. "It's Gambino vs Serbians or Genovese vs Russian Mafia, he said."It's a more diverse playing field today."

But organized crime does not have the same checks and balances as legitimate businesses, making violence the only way of resolving disputes.

Gangsters in a patrol wagon hiding their faces from the camera as they head to the office of the special prosecutor during the mid-1930s.

The Mafia sometimes works with drug kingpins

American mob groups may be involved in other businesses, but they still sell drugs. Just not on the same global scale as the cartels, Kenney said.

"The struggle going between Mexico cartels influences drugs sold in Europe, they're fighting over global markets. Less so groups in New York, they're fighting over localized version of same thing," Kenney said.

"They can't do the [same] volume of business because they don't have the product that the Colombians and Mexicans are able to produce. But they can collaborate with those groups to become part of the distribution network."

But Schumacher cautioned against drawing distinctions between how the mob and cartels operate since their motivations are essentially the same.

"They all want to make money illegally," he said. "There's not a lot of glory in it, there's not a lot of joy in what they do, but there's a lot of money."

New York mobsters are the most dominant

Movies such as "The Godfather" trilogy glamorized American mobsters and led to a fixation on New York's five families.

Beyond Hollywood, New York crime families received the most attention because of the large media presence in the city, Kenney said.

This contributed to an exaggerated impression of the power and reach of New York's five families, obscuring the influence of other mob groups in Chicago, Kansas City and Detroit, among other cities, he said.

In reality, a national syndicate linked organized crime groups in almost every major city, Schumacher said. But that doesn't really exist anymore.

Of all the America organized crime groups, New York's five families have been the most resilient, Schumacher said.

Police arrest a man in Cali's killing

Old perceptions of the American Mafia persist, leading to familiar theories about why a gunman targeted Cali.

Shapiro offered several scenarios. One is it could be personal, such as revenge for an affair or something unrelated to his Mafia ties. Or, it could be a rival looking to gain his turf or a competitive edge.

Police said they arrested a 24-year-old man Saturday and will extradite him to the borough of Staten Island, where the killing happened. There, he will be formally charged with murder.

While police have not revealed a motive for the alleged shooter, a source with knowledge of the investigation told CNN on Sunday that the shooting did not appear to mob-related.

The source said that the suspect, Anthony Comello, had some kind of relationship with one of Cali's family members, and Cali disagreed with the relationship. Comello took offense to that, the source said.

Robert C. Gottlieb, an attorney for Comello, said in a statement that Comello's family and friends "cannot believe what they are hearing."

"There is something very wrong here," Gottlieb said, "and we will get to the bottom of it."

"While we believe we have the shooter in custody for this incident, the investigation is far ... from over," NYPD Chief of Detectives Dermot Shea said.

"The investigation will turn to were other parties involved in this, gathering future and additional evidence and working on the motive for this particular crime."