SCOTT SIMON, HOST:

In Argentina the case of a dead prosecutor has riveted the country and caused a political crisis. Alberto Nisman was found in his apartment with a bullet to the head just over a month ago. That was after he accused Argentina's president of being involved in a cover-up. It is still not known how he died. The mystery deepens, the cast of characters fascinates and NPR's Lourdes Garcia-Navarro reports that Argentina is preoccupied with conspiracy.

LOURDES GARCIA-NAVARRO, BYLINE: The locksmith, the journalist, the computer technician, the waitress, the carpenter - no, this isn't a job fair.

ADRIAN BONO: This is a murder mystery. Every single day we discover there's a new development that could potentially change the entire case.

GARCIA-NAVARRO: And one of the strangest parts - these developments, or plot twists, says journalist Adrian Bono, come in the form of people.

BONO: A lot of people have been discussing this on social media, how there are these particular characters that show up and they grab our attention for a few days and then they disappear.

GARCIA-NAVARRO: So bear with me here while I give you the background to a very complicated case. Alberto Nisman was a famous prosecutor in Argentina. He was investigating the country's worst-ever terror attack - a bombing of a Jewish community center in 1994. He built a case showing that Iran masterminded the attack. He then accused the government of Argentina, the president and some of her ministers of being involved in a cover-up because they wanted to cement an oil for grain deal with the Islamic Republic. Needless to say, the charges were explosive. And when he was found with a bullet to the head, many in Argentina believed it was murder. The entire investigation has played out in the public realm, starting in the first few days after Nisman's death when a humble locksmith was called in to testify. And he was swarmed by reporters.

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UNIDENTIFIED PEOPLE: (Foreign language spoken).

UNIDENTIFIED MAN #1: (Foreign language spoken).

GARCIA-NAVARRO: He'd been brought in by Nisman's mother to open the door to her son's apartment when he didn't respond to phone calls. The next figure to gain a brief notoriety was the journalist Damian Pachter. He broke the news of Nisman's death on Twitter and then suddenly he told everyone - again through the media - that he was being followed and his life was in danger and he fled the country to Israel.

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DIEGO LAGOMARSINO: (Foreign language spoken).

GARCIA-NAVARRO: After that, a computer expert who gave Nisman the gun, which was found next to his dead body, became a subject of fascination. Diego Lagomarsino gave a teary press conference where he said Nisman had asked him for the gun and that he had nothing to do with the prosecutor's death.

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UNIDENTIFIED MAN #2: (Foreign language spoken).

UNIDENTIFIED MAN #3: (Foreign language spoken).

GARCIA-NAVARRO: And right now, as you can hear here, all the airwaves are obsessing over a waitress and a carpenter. Argentina has this unusual system where people are picked up off the street and taken to crime scenes to act as impartial witnesses. A 26-year-old waitress and a carpenter were there during Nisman's crime scene investigation. And, again through the media, they came out and said that the crime scene was compromised, which has set off another firestorm.

CAROLINA BARROS: Everything in Argentina has to be placed in a conspiracy theory - everything.

GARCIA-NAVARRO: Carolina Barros is a journalist and the ex-editor-in-chief of the Buenos Aires Herald. She says even the president of the country, Cristina Fernandez de Kirchner, came out on national television giving her conspiracy theories on Nisman's death. And in the cafes and bars, regular people are talking, too.

BARROS: Everybody is an expert on what's going on and everybody is a Sherlock Holmes here.

GARCIA-NAVARRO: Part of this has to do with Argentina's murky, bloody history. It's suffered a brutal dictatorship, where people were disappeared, where babies were stolen to be brought up by their real parents' torturers. Conspiracy theories in Argentina often turn out to be true. Barros says, though, that all this interest in these characters has acted as a kind of distraction.

BARROS: Some of them say A, some of them say B, and this is a great mess, a great soap opera, and what is going on regarding the truth.

GARCIA-NAVARRO: Jose Luis Fernandez is a sociologist at the University of Buenos Aires.

JOSE LUIS FERNANDEZ: (Foreign language spoken).

GARCIA-NAVARRO: He says people are concentrating on the frivolous to avoid thinking about the dark heart of this story. It began with the murder of dozens of people in a bombing that is still unresolved and despite the endless stream of characters appearing on TV to talk about what they know about the case, no one believes in Argentina that they will ever find out what really happened to Alberto Nisman. Lourdes Garcia-Navarro, NPR News, Buenos Aires.