The most prominent leader of these groups is Luis Posada Carriles. Mr. Posada worked for the CIA for many years; he helped organize the Bay of Pigs invasion of Cuba and helped funnel arms to the Nicaraguan Contras. There is overwhelming evidence that he planned the bombing of a Cuban civilian airliner in 1976, which killed 73 people. He has admitted organizing the bombing of hotels and restaurants in Havana in 1997, in which an Italian tourist was killed and many others injured. In Panama in 2001, he was convicted of plotting to blow up an auditorium where Fidel Castro was to speak. After being pardoned by the Panamanian president, he returned to Miami, where he currently lives, a free man. Although the U.S. Justice Department has called Mr. Posada "an admitted mastermind of terrorist plots and attacks," U.S. authorities have failed to prosecute him for any of these crimes and have refused to extradite him to Cuba.