Eleven of 21 prison gang leaders accused of directing killings and drug sales from within penitentiary walls have pleaded guilty to racketeering, prosecutors said.
The remaining 10 leaders of the military-styled Nuestra Familia, including its three top generals, await trial next year in a sweeping case that grew unexpectedly out of an arrest in Santa Rosa, Calif. six years ago.
Despite the guilty pleas, police and prosecutors are reluctant to claim victory, saying new leaders are being groomed to succeed the men accused of masterminding a powerful crime network from their cells at Pelican Bay State Prison in Crescent City. 
Plea bargains with 10 men and one woman who held various ranks from gang associate to regional commanders have been completed over the past three months, said Matt Jacobs, a spokesman for the U.S. attorney in San Francisco.
Four of the defendants have been sentenced so far, receiving terms ranging from nine to 15 years, prosecutors said.
They are to be scattered in prisons throughout the country, authorities said, in order to break up the clandestine communication network used to order crimes such as methamphetamine sales and murder.
Federal prosecutors plan to go after the next level of Nuestra Familia leaders in trials starting next year.
The top three in the chain of command were serving life sentences in Pelican Bay when they were rolled up in a sting that began with the arrest of a parolee at a Santa Rosa bus station.
In the investigation, dubbed Operation Black Widow, detectives said they decoded messages sent from gang leaders in prison to members on the outside in places including Santa Rosa, Salinas and Stockton.
In 2001, a federal grand jury issued indictments accusing gang leaders of ordering executions and other crimes from inside Pelican Bay.
Authorities said it is possible that some of the gang members who have already pleaded guilty will testify in the coming trials in a specially modified high-security courtroom in San Francisco.
Before the top tier is tried, a mid-level group of captains and lieutenants is scheduled to face a jury trial beginning Jan. 5.
Meanwhile, the gang commanders have been moved from Pelican Bay to special federal holding cells inside the county jail in Oakland.
The men are segregated from other inmates, but county jail officials said they are confined beside each other in one-person cells.
Santa Rosa police have complained that the arrangement allows the leaders to maintain communication and carry on gang business as usual -- exactly what authorities sought to end with Operation Black Widow.
Federal prosecutors declined to comment on the custody arrangements for the defendants.