Mastermind Behind Amazon Murders of Journalist and Activist Caught in Brazil

An illegal-fishing trafficker ordered henchmen to kill an expert on Indigenous tribes in June because he was disrupting the illicit game trade, Brazilian authorities said Monday, leading to an assassination that also left a British journalist dead. The killings attracted international attention to the bloody conflict over the Amazon rainforest.

Brazilian federal police officials said they had gathered evidence that showed Rubén Dario da Silva Villar, a Colombian man widely known as Colombia, had ordered the killing of Bruno Pereira, 41, an activist and former Brazilian government official, because he was helping Indigenous tribes combat illegal fishing and hunting.

As a result, they said, he was hurting Mr. Villar’s business.

When other men went to carry out the orders, pursuing Mr. Pereira in a boat and shooting him with shotguns, they also killed the person he was with: Dom Phillips, 57, a British freelance journalist who had written for The Guardian and The New York Times and was traveling in the Amazon at work on a book.

Mr. Villar is now at least the fourth man arrested in the murders of Mr. Pereira and Mr. Phillips. The federal police have also charged three other men with killing the men or helping to hide their bodies. The police said they were also searching for another man who they believe gave one of the murder weapons to the gunmen and later helped to hide the bodies.

Law enforcement officials said they planned to charge Mr. Villar with the murders, largely ending the investigation into the killings. But Indigenous activists in the region said more work needed to be done.

“Who is financing these people so they can continue their illegal activities?” asked Eliesio Marubo, a lawyer with Univaja, an Indigenous association that, along with Mr. Pereira, helped organize patrols of the region. “The federal police didn’t answer that. We need a deeper investigation.”

The police said that they believed Mr. Villar ordered the killings based on testimony from witnesses and records that showed he supplied the ammunition used in the killing and paid for the lawyers of one of the gunmen.

The Times was unable to contact Mr. Villar or a lawyer representing him. A lawyer who had been working on his behalf said he had left the case.

Mr. Pereira and Mr. Phillips were traveling deep in the Amazon in early June to meet with a group of Indigenous men who were patrolling the Javari Valley, a remote Indigenous reservation the size of Portugal that is home to at least 19 isolated groups.

The Indigenous men had taken up the patrols in an effort to fight rampant illegal fishing and hunting in the region, which had increased after the Brazilian government largely abandoned the area, particularly under the administration of the former far-right president, Jair Bolsonaro.

Mr. Pereira, who was once Brazil’s former top official on isolated tribes, was training the Indigenous men to document crimes using smartphones and drones, and Mr. Phillips was interviewing them for a book he was writing about the way people were trying to save the Amazon.

The Indigenous patrols had been successful at times, including leading authorities to a poacher with 650 pounds of illegal game and nearly 900 pounds of illegal fish. The patrols had upset Mr. Villar, who had run a trafficking operation in the area, a violent, crime-ridden region of the rainforest on the border of Brazil, Colombia and Peru, police said.

The police first arrested Mr. Villar in July for using a false identification when questioned about the murders. He was later released. The police arrested him again in December for breaking the rules of his previous release. He has been in detention since.