Brazilian Federal Police identified the suspect as Amarildo da Costa de Oliveira. Police said he confessed on Tuesday night and indicated where their bodies had been buried. The following day, the suspect took police to the area where the pair were allegedly murdered.
According to Federal Police representative Eduardo Alexandre Fontes, police are currently excavating the area and found human remains, which will be sent to Brasilia for forensic analysis on Thursday.
Police said the second suspect, a 41-year-old man, was being interrogated and would be referred to a custody hearing in the municipal court. They also said they seized some firearm cartridges and a paddle, which will be analyzed.
Phillips and Pereira disappeared while conducting research for a book project on conservation efforts in the region, which authorities have described as “complicated” and “dangerous,” and known to harbor illegal miners, loggers, and international drug dealers.
They had reportedly received death threats just days prior to their disappearance.
Between 2009 and 2019, more than 300 people were killed in Brazil amid land and resource conflicts in the Amazon, according to Human Rights Watch, citing figures from the Pastoral Land Commission, a non-profit affiliated with the Catholic Church.
And in 2020, Global Witness ranked Brazil the fourth most-dangerous country for environmental activism, based on documented killings of environmental defenders. Nearly three quarters of such attacks in Brazil took place in the Amazon region, it said.
Phillips had reported extensively on Brazil’s most marginalized groups and on the destruction that criminal actors are wreaking on the Amazon.
CNN’s Kara Fox and Juliana Koch contributed to this report.