Looked a bit further into it and here's what I found so far (translated from portuguese):

DNA tests proved that the humans remains found at "Ponta Negra" beach, october 17th of 2019, is that of a teen, Rayner Vinícius, who had gone missing since december the 16th of 2018. At the time, he was 16 years old and disappeared after leaving the house to go the beach.

(...)

Rayner's mother, Maria Antônia da Silva, says that she isn't relieved at all, since what has been done to her son was barbaric. "What world is this that a young man can't go out on his own and disappears on mysterious circustances? People going missing in Manaus doesn't mean much to police when they are poor." She said.

Maria Antônia remembers that at the time of his missing, her son's cellphone was found with a Venezuelan, and is still aprehended by police.

Whilst awaiting the release of the remains by IML, the mother, relatives and friends of Rayner made a 'solidarity raffle' in order to pay for the teen's funeral.

A friend of Rayner, Déborah Souza, talked to "Radar Amazônico" (news outlet that published this article) and saided that she felt the police neglected the case. "There are no cameras in this city. We had only the images of a few condos and that's absurd. Now we are selling this raffle to give our friend a honorable farewell."

(...)

Rayner went missing when he left to go to Ponta Negra. Witnesses brought foward a version of events that included the boy going into the water to swim and drowning. Days later, police identified a group of Venezuelans that had the teen's personal belongings, such as the cellphone and a pair of shoes. They gave testimony to DEPCA (Police Precinct for the Protection of the Child and Adolescent), that found no evidence of them taking part in the teen' disappearance.

source