RIO DE JANEIRO -- Homicide investigators said Wednesday that they would charge 10 police officers with torture and murder in the disappearance of an impoverished construction worker from Rocinha, one of Rio de Janeiro's largest slums, the latest development in a case that has been a festering source of tension here for months.
The disappearance in July of the 42-year-old laborer, Amarildo de Souza, set off street protests against police brutality in Rio, São Paulo and other Brazilian cities. The demonstrations were part of a broader buildup of anger over crackdowns on demonstrators by Brazilian security forces this year that has included the widespread use of rubber bullets, tear gas and pepper spray.
Details emerging about Mr. de Souza's case included graphic details about what investigators described as torture at the hands of police officers in Rocinha, may feed into the exasperation with Rio's police forces, even as the city prepares to host the World Cup next year and the Olympics in 2016.
According to the newspaper O Globo, which initially reported on the investigation's findings on Tuesday night, investigators found that officers had submitted Mr. de Souza to electric shocks and asphyxiation with a plastic bag after he was detained for questioning in a sweep of drug trafficking suspects in Rocinha, a hillside favela, or slum, which overlooks some of Rio's most exclusive residential districts.
Rivaldo Barbosa, a police investigator in the case, told reporters Wednesday that he could not confirm precisely where Mr. de Souza had been tortured.
Relatives of Mr. de Souza, the father of six children, have stated repeatedly that he had no involvement in drug trafficking. Even though some details of Mr. de Souza's disappearance remained unclear, including the identification and location of his remains, his family cautiously welcomed the announcement that officers would be charged in his killing.
"They should pay for what they did," said Elizabete Gomes da Silva, 47, a maid who is Mr. de Souza's widow. "Everyone knows what they did," she said, referring to the police officers involved. "My husband isn't coming back."
Casting more doubt over the so-called pacification of some of Rio's favelas, a process in which the police have recently asserted control over big sections of the city, investigators said that Maj. Edson Santos, the police commander in Rocinha at the time of Mr. de Souza's disappearance, bribed two witnesses in the case so that they would claim drug traffickers were to blame in the crime.
The two witnesses later recanted their testimony and entered Brazil's witness protection program. The charges in the case are one step in what could result in a lengthy trial. A judge still needs to order the arrest of the officers, a move expected in the coming days, and prosecutors will examine the testimony and evidence obtained so far.
Ignacio Cano, a researcher on police violence at the State University of Rio de Janeiro, said it was encouraging that police investigators were able to carry out an independent inquiry, reflecting some advances in making Rio's police more accountable for their own crimes. Still, "this case shows how it would be naïve to think that an entire police force could change overnight," he said.
Lis Horta Moriconi contributed reporting.
This article originally appeared in The New York Times.