Federal authorities today struck what they hope will be a fatal blow to this city's largest and most ruthless street gang.

After a federal grand jury returned indictments against 39 people Wednesday, more than 250 federal, state and local law enforcement officials moved in on gang leaders this morning in a predawn raid named "Operation Headache."

By mid-afternoon, 22 allegedly high-ranking members of the "Gangster Disciples," which boasts a membership of thousands, were in custody. Law enforcement officials said they expect to arrest the remaining defendants within a week, including Sonia Irwin, a Chicago police officer who is rumored to have been living with Gregory Shell, the gang's second in command.

"We have taken off the top echelon and we have bitten off the head of the snake," James Burns, U.S. attorney for the Northern District of Illinois, told a press conference. "This has been going on for 25 years and we needed to attack at the top. This organization is going to be greatly crippled now."

The indictments charge gang leaders with conspiracy to distribute cocaine, crack, heroin and marijuana as well as 45 other counts, including violation of gun control laws and extortion. The gang has allegedly been involved in numerous acts of violence and is suspected of running a drug and money-laundering operation that spanned the Midwest.

For 25 years, Larry Hoover, 44, has been the undisputed leader of the Disciples. He is accused of running a tight and ruthless multimillion-dollar ship from his cell at the state prison in Dixon, Ill., where he has been serving a 150- to 200-year term for a 1973 murder. The operation has flourished in Chicago and the surrounding suburbs despite the fact that more than 1,000 of its members are serving time, according to law enforcement estimates. Just this year, the gang allegedly has been responsible for more than 12,000 crimes including an estimated 80 murders, officials contend. Hoover, also known as "The King" and "The Chairman" was arrested and moved into federal custody today.

The raid came as a surprise to many who believed Hoover when he publicly announced he was going to "come clean" two years ago. It was then that he helped found 21st Century VOTE, a political group aimed at reforming and organizing gang members into a political force in the city. He also started "Save the Children Promotions," a corporation he organized with his common-law wife that sponsors rap concerts with some proceeds going to children's causes.

Federal law enforcement officials and the Internal Revenue Service -- which also participated in today's raid -- allege the two businesses are nothing more than money-laundering fronts through which much of the gang's estimated annual $10 million in drug profits has been run. Yesterday's indictments seek forfeiture upon conviction of the money and seven cars, including five luxury vehicles and a race car.

After 25 years of living under gang domination, many residents of the poor neighborhoods where the Gangster Disciples ruled appear skeptical that today's arrests will make a difference.

"They've gone and done this for so long and right from their jail cells that I don't think this is the end of it. {Hoover} can still talk on the phone, still get things done and as long as there is even one member out there this is going to live," said a resident of Dalton, a Chicago suburb, who asked to remain anonymous. He lives down the street from two of the gang members arrested in the raid.

But Tom Kirkpatrick, director of the Chicago Crime Commission, disagrees. "The whole structure of the organization is gone and we're grateful for that. These were the main guys for 22 states and 66 cities. It's over."

All gang members, the indictment charges, were required to sell drugs supplied by high-ranking Disciples with profits going back to the top leaders. Punishment for failure to comply with the gang's "laws" ranged from fines to murder.

"That is how {Hoover} was able to maintain his control," said Burns. "An incredible element of fear and terror, of beatings or murder, was always present among members."