STORY: Dozens gather in Sao Paulo to protest the murder of British journalist Dom Phillips and indigenous expert Bruno Pereira.
Holding banners calling for justice, local residents and indigenous people all condemned the crime.
Police investigating the murders said on Saturday (June 19) they had arrested a third suspect who gave himself up at a police station in the remote Javari Valley.
Phillips and Pereira went missing in the Amazon rainforest nearly two weeks ago.
They were last seen on June 5 travelling through the region on a boat.
Their remains were found earlier this week.
Police said both had been shot with hunting ammunition.
They have arrested a local fisherman, who confessed to killing the two men, and his brother, who was taken into custody earlier this week.
According to the police, the killers acted alone, but the local indigenous group Univaja disputes this,
It says it has informed officials numerous times of an organised crime group operating in the region.
Phillips, a freelance reporter who had written for the Guardian and the Washington Post, was doing research for a book on the trip with Pereira.