CHICAGO — The names read like a who's who from some faded blotter left behind at the Chicago Police Department's old State Street headquarters: Joey "the Clown" Lombardo, Frank "the German" Schweihs, Frank "Gumba" Saladino, and on and on.

But on Monday, 14 of these accused Chicago mobsters, including several who have for years been reputed to be in the city's top level of organized crime leaders, were being rounded up in connection with 18 murders that stretch back over four decades and had gone unsolved and, in some cases, had been nearly forgotten.

Several of the accused are in their mid-70s now, and one, though only 59, was found dead, apparently of natural causes, when the authorities arrived on Monday to arrest him in the hotel room where he lived. A few of the others accused, meanwhile, had moved away, to places like Florida and Arizona, better known for retirement.

Describing the 9-count, 41-page racketeering conspiracy indictment as putting a "hit on the mob," Patrick J. Fitzgerald, the U.S. attorney here, said in a written statement, "After so many years, it lifts the veil of secrecy and exposes the violent underworld of organized crime."

While arrests of organized crime figures are hardly unique in a city where Al Capone once worked, rarely have so many of its reputed high-level leaders been charged all at once or has the entire "Chicago Outfit" been officially deemed a criminal enterprise under federal racketeering laws.

"This really lays out the whole continuing criminal enterprise that is still going on," said Thomas Kirkpatrick, president of the Chicago Crime Commission, a nonprofit anticrime group created in 1919 by Chicago business leaders who were increasingly worried that it could become too dangerous to conduct legitimate commerce in this town.

"People tend to forget what these guys are about," Kirkpatrick said. "They watch 'The Sopranos' or some of these movies about the mob, and they think it's just some colorful characters. The thing is, they're still doing this. These characters are still doing this."

Among the most notorious murders the authorities say they have solved with Monday's announcement: the 1986 death of Tony "The Ant" Spilotro, the organization's chief enforcer in Las Vegas, and his brother, Michael, who were buried alive in an Indiana cornfield. (Joe Pesci portrayed a character based on Tony Spilotro in the 1995 movie "Casino.")

The authorities here say the indictment, which was returned by a federal grand jury on Thursday and unsealed on Monday, was years in the making. The FBI called its inquiry "Operation Family Secrets," and agents from the FBI and the Internal Revenue Service began arresting the accused in Illinois, Florida and Arizona on Monday morning.

The indictment reads like a grade school textbook on Chicago's organized crime web, laying out its command structure (a boss, an underboss and crew bosses), its business endeavors (absurdly high-interest loans, sports bookmaking and video gambling enterprises), and its methods of avoiding the police (listening to police radios, talking on pay phones and using remote control devices to keep away from actual murder scenes).

Among those indicted were men the authorities say guided three of the city's crucial neighborhood "crews": James Marcello, 63, of the Melrose Park crew; Frank Calabrese Sr., 68, of the South Side/26th Street crew; and Lombardo, 75, of the Grand Avenue crew.

Lombardo, who lives in Chicago, was one of two among the accused whom authorities were still seeking on Monday evening. On Monday afternoon, Rick Halprin, an attorney for Lombardo, said he did not know where Lombardo was and was uncertain whether Lombardo was even aware of the charges against him.

Half a dozen attorneys who have worked in the past for some of the 13 others accused of crimes did not return telephone calls from a reporter late Monday.

Eleven of the men are charged with racketeering conspiracy, including planning or agreeing to commit murder on behalf of the Outfit or taking part in other illegal activities like collecting "streets taxes," running gambling operations or obstructing justice on behalf of the organization. The three others were charged with illegal gambling or tax conspiracy.

Two retired Chicago police officers were among those arrested. The indictment says that when Anthony Doyle, now 60, was on the Chicago force, he helped a mob leader by keeping him informed on an investigation of one of the unsolved killings. When that leader went to jail at one point, he passed messages from him to other members of the Chicago Outfit, according to the document.

The indictment accuses Michael Ricci, who is 75 and also retired from the police department and from the Cook County's sheriff's department, of helping to pass messages from a jailed mob leader to others and of collecting money the leader was extorting from people.

Federal authorities declined to say how they had now solved 18 murder cases dating from 1970 to 1986, but Kirkpatrick, of the Crime Commission, said that he understood that the authorities had been helped, in part, by analyzing DNA evidence using technology that had been unavailable at the time of the crimes.

On Monday, the authorities said their investigation would continue and that more arrests were possible.

The indictment itself has already spurred at least one new set of mysteries. When agents on Monday arrived to arrest Saladino, 59, they found him dead in the hotel room in Kane County, west of Chicago, where he had been living. Beside his body was tens of thousands of dollars in checks and cash. The authorities would not say where the money had come from.

Contributing: Gretchen Ruethling.