In late September 1976, a radio-controlled bomb blew up a car in DuPont Circle in Washington, D.C., killing Orlando Letelier, Chile's ambassador to the United States, and his assistant, Ronni Moffitt, an American citizen.

More than a decade later, Armando Fernandez-Larios, a former army major who served under Gen. Augusto Pinochet, stepped before a federal judge in Washington to take responsibility for his role in the killings. The judge applauded his guilty plea and sentenced him to credit for time served. Then, Fernandez-Larios dropped out of sight.

Now, an exiled family of a young economist murdered by the Chilean military in 1973 contends that Fernandez-Larios should step forward again to take responsibility for that death. In Miami federal court, the family of Winston Cabello is suing for unspecified damages under the Alien Tort Claims Act, and the more recent Torture Victim Protection Act, which permits victims to sue in a U.S. court over incidents of torture abroad.

The suit contends that Fernandez-Larios was one of those who tortured Cabello and at least 70 others in northern Chile the month after Pinochet seized power from President Salvador Allende.

The case emerges at a time when the fate of Pinochet himself is near resolution in England, with magistrates in the House of Lords poised to decide whether he may be extradited to Spain to answer charges of crimes against humanity committed in Chile by his regime between 1973 and 1990.

For Fernandez-Larios, the veil of several years of anonymity was lifted last Friday when a local process server hand-delivered court papers announcing that he is a defendant in Case No. 99-528. Reached Tuesday at his condominium home in Miami-Dade, he told The Herald that he would be willing to discuss the case, but only after consulting his lawyer.

Fernandez-Larios appears to have lived and worked in obscurity over the years since making his admissions in the Letelier case in 1987. At the time, he said he surrendered voluntarily because he considered himself to be a ``marked man'' in Chile.

Before U.S. District Judge Barrington Parker, Fernandez-Larios pleaded guilty to a reduced charge of accessory to murder, and testified that his role was limited to traveling to this country on a false passport, locating Letelier's office and identifying his car.

Replied the judge: ``The defendant Fernandez has taken a giant step in offering his plea.'' Parker added that Fernandez had ``pulled back the cover'' by superiors to conceal the roles of others in the assassination.

After his court appearance, Fernandez-Larios was reported to have entered the federal witness protection program.

The Center for Justice & Accountability, a San Francisco legal organization that draws financial support from Amnesty International and the United Nations, retained an investigator to find him.

``There was after the time he came to the United States in 1987 rumors that he entered the witness protection program,'' Shawn Roberts, the center's legal director, said Tuesday. ``At the end of last year, our clients started hearing rumors that people in the Chilean community in the U.S. heard that Fernandez-Larios might be working in Miami.

``We heard initially that people thought he was working in an art gallery,'' Roberts said. ``We found he had some small businesses. Between December of '98 and February we started putting together the pieces, but we weren't actually sure until we delivered the papers to him Friday.''

Paul Hoffman, a human rights lawyer in Santa Monica, Calif., who is helping to prosecute the lawsuit, said one of the center's purposes is to track down alleged human rights violators and hold them legally accountable for their alleged offenses.

``There is an issue about whether people who committed serious human rights crimes can go about their lives in the United States,'' he said. ``We sue them because they are here. If they have money, we intend to get it.''

The Cabello family has not specified how much money it is seeking. Some judgments in similar cases have ranged from $15 million to $20 million, Hoffman said.

``There have been difficulties with payment, there have been some collections -- that's one of the difficulties in these cases,'' he said. ``In a case like this, it could be millions of dollars. You're talking about the killing of a young economist in his late 20s. He had a long life ahead of him.''

Fernandez-Larios, who according to state records in 49 years old, has until April 8 to formally respond to the lawsuit.