The fight originated when Gilson Ramos da Silva, 21, a.k.a. "Gilson Aritana," a member of the ADA ("Amigos do Bairro") gang led other members into the "morro da Mineira" (Miner Hill) to sell drugs, Ricardo Teixeira Dias, a local police official said. The region is controlled by rival gang Comando Vermelho (Red Command), which does not approve of other gangs selling drugs in the region. Comando Vermelho members started attacking the rival members of ADA to protect their turf.
Ramos da Silva killed 11 people.