The exception is Joo Moreira Salles. A documentary filmmaker, Salles (brother to Oscar-nominated director Walter Salles) has spent much of his career tramping up and down those ragged hillsides. Earlier this year he won a prize for a film–“Dispatches From a Private War”–that explores the favelas. That’s how he met Marcio Amaro de Oliveira, or “Marcinho VP,” a hardheaded, smooth-talking former drug lord who used to preside with an iron hand over Dona Marta, one of Rio’s toughest neighborhoods. That’s also how Salles got into trouble with the law. Last May the filmmaker was indicted for aiding a fugitive criminal because he paid Marcinho VP a four-month stipend to write a book about his life on the far side of the law. If convicted, Salles could conceivably be sent to jail for up to one year. The case is under review by the district attorney’s office. But it has already produced howls in the Brazilian press and among the upper strata of Rio society–partly because Salles is also heir to a banking fortune.

Before he met Salles, Marcinho VP was just one more small-time Rio bandit. He claimed his 15 minutes of glory when he reportedly charged Michael Jackson a fee for filming a music video on his turf. But Salles saw beyond the brassy facade. Over the months, the two of them spoke at length about Che Guevara and the rebels in Chiapas. Salles lent him books by Albert Camus, while Marcinho VP waxed defiant about his plans to start a movement to champion the downtrodden favela dwellers.

“He was charismatic, intelligent and eloquent,” Salles says. The filmmaker was also moved by a story Marcinho VP told about how his boyhood dream of becoming a graphic artist was crushed when his classmates laughed at his shabby clothes and taunted him for living in the favelas.

So Salles decided to help. He would pay the drug trafficker to write his tale on the condition that Marcinho VP drop out of the drug world. It was typical of Salles, whose films invariably tackle social topics (one followed footballers from slums to the big leagues; next is a look at poor evangelicals). He once taught video-making while filming in Kenya. He also lectured on Renaissance painting to the residents of Dona Marta, including a dozen or so drug traffickers who brought their guns to class. “You couldn’t meet a more ethically correct person in your life,” says Rubens Cesar Fernandes, a Rio anthropologist. Not everyone agreed. The money only came to $2,600–but Marcinho VP was not just an innocent ghetto kid who’d gone astray. He had been tried in absentia, convicted for drug trafficking and conspiracy and condemned to 25 years in prison. Police also suspect he was involved in several murders.

The controversy is reminiscent of the one that author Norman Mailer sparked in the United States in the early 1980s. Mailer never quite repented for believing in Jack Henry Abbott, the convict turned writer who won parole with Mailer’s backing, but then killed a man in a brawl. ‘‘I’m sorry as hell about the way it turned out,’’ Mailer told reporters, but added, ‘‘I’m willing to gamble with certain elements in society to save this man’s talent.’’

Salles took that same gamble and may go to jail for it. Even now, he says he would do it again. “I believe in Marcio. That’s why I urged him to leave the world of crime. In a way, he is also a victim, society’s victim.” Relatives of the victims of the former drug king of Dona Marta might be forgiven for not seeing things quite that way. Now in jail, Marcinho VP may still have the chance to tell his side of the story. And all the time in the world to write that book.