Charges against accused bomber of Cuban airliner killing 73 people dropped by U.S.

If the government appeals, it would challenge the judge's decision to toss out the indictment based on her analysis that the interpreter failed to accurately translate questions posed to Posada at his citizenship interview and his responses.

The judge said the interpreter, Luis Granados, used wrong words, omitted others or added words of his own to some questions and answers.

''This is not an acceptable practice in interpretation, and it caused severe confusion during the interview,'' Cardone wrote.

For example, a government lawyer -- who was with Granados -- tried to ask Posada if he had been to Mexico after he completed his jail time in Panama, where he was imprisoned in connection with a plot to kill Fidel Castro. Granados, instead, asked Posada whether he had been to Mexico before his jail time in Panama.

The judge noted that the blunder could ''cause numerous problems'' because the discrepancy undercut the United States' own timeline of how and when Posada entered the country -- which is the crux of the indictment.

Cardone questioned why immigration authorities interrogated Posada at his citizenship interview not only about his entry into the United States but also about his alleged role in anti-Castro militant activities, such as the bombings of a Cuban airliner in 1976 that killed 73 people and at tourist sites in Cuba in 1997 that killed an Italian.

She indicated the government questioned Posada on these activities to deepen its criminal investigation of Posada as a terrorism suspect, not to establish that he violated immigration law.

''The realm of this case is not, as some have suggested, terrorism,'' she wrote. ``It is immigration fraud.''

An immigration judge in El Paso ordered Posada deported to any country, except Cuba or Venezuela. As a foreign national facing a final deportation order, Posada is subject to detention by the United States until authorities find a country willing to take him.

The U.S. Supreme Court in 2001 prohibited indefinite detention for foreigners who cannot be deported, but it exempted those classified as detainees in ``special circumstances.''

Immigration administrators argue that Posada fits that category because his release could have ''serious adverse foreign policy consequences.'' But a federal magistrate in El Paso said that for the United States to continue holding Posada, it would have to classify him as a terrorist, and recommended his release.