Defense lawyers for two anti-Castro Cubans on trial for the second time for the 1976 car bombing assassination of former Chilean ambassador Orlando Letelier told a federal jury yesterday that their clients were "scapegoats" in a conspiracy between the prosecution's star witness and the Chilean secret police to kill Letelier and put the blame on the Cubans.

That theory, presented in opening statements yesterday, contrasted sharply with defense arguments at the original trial in 1979 that the assassination was masterminded by the U.S. Central Intelligence Agency and that the witness, Michael Vernon Townley, acted as a double agent for the CIA and DINA, the Chilean secret police.

During his opening statement in U.S. District Court, defense lawyer Paul Goldberger only briefly mentioned evidence that Townley had once offered his services to the CIA and that a branch of the agency had approved him for "operational" services.

Instead, Goldberger emphasized that the secret police had targeted Letelier because of his outspoken criticism of the military regime of Augusto Pinochet, and that Townley was order to carry out the assassation and told to shield Chilean officials from any culpability.

"Townley got instructions in Chile to use the Cubans," Goldberger told the jury. "And that's exactly what he intended to do, lay it on the Cubans."

Assistant U.S. Attorney Cary M. Feldman, in his opening statement to the jury, said the government will prove that Townley, on instructions from DINA officials, recruited the Cubans to help him carry out the Letelier assassination.

Feldman agreed that DINA wanted to protect itself from implication in the murder. He said DINA got willing support from anti-Castro Cubans in the United States. Feldman is prosecuting the case along with Assistant U.S. Attorneys E. Lawrence Barcella Jr. and H. Lowell Brown.

The two defendants, Guillermo Novo Sampol and Alvin Ross Diaz, are both members of the Cuban Nationalist Movement, which had dealings with the Chilean government, Feldman said. The relationship was best described in a 1976 letter signed by Novo to a Chilean official in which he said, "The CNM has intrepidly defended the best interests of the Pinochet government in every way public and private worthy of comment and worthy of silence," Feldman told the jury.

Defense lawyer Goldberger also told the jury that they will hear parts of a transcript of portions of a telephone call made from the U.S. attorney's office in Washington to Chile by Townley in which Townley said he would get friends to threaten Judge Barrington D. Parker, who is presiding at the trial. Goldberger said the comments will show that Townley, whom he described as a "mild mannered Clark Kent," had no respect for the judicial system.

The telephone conversation took place in January 1979, at the end of the first trial of Guillermo Novo and Ross, both of whom are charged with conspiracy and murder of Letelier and Ronni Karpen Moffitt, an associate of Letelier's at the Institute for Policy Studies in Washington. Two other Cubans and three Chileans, including the DINA head, have been indicted for the killings but have not yet stood trial.

A tape of the conversation, the origin of which is unknown, was made available to the defense at that time.