The Pacifying Police Unit, abbreviated UPP, is a law enforcement and social services program pioneered in the state of Rio de Janeiro, Brazil, which aims to reclaim territories, most commonly favelas, controlled by gangs of drug dealers. The program was created and implemented by State Public Security Secretary José Mariano Beltrame, with the backing of Rio Governor Sérgio Cabral. The stated goal of Rio's government is to install 40 UPPs by 2014. By May 2013, 231 favelas had come under the UPP umbrella. The UPP program scored initial success expelling gangs, and won broad praise. But the expensive initiative expanded too far, too fast into dozens of favelas as state finances cratered, causing a devastating backslide that enabled gangs to recover some of their lost grip.

Batalhão de Operações Policiais Especiais (BOPE) is the police tactical unit and gendarmerie of the Military Police of Rio de Janeiro State (PMERJ) in Brazil. Due to the nature of crime in favelas, BOPE units utilize equipment deemed more powerful than traditional civilian law enforcement, and have extensive experience in urban warfare as well as progression in confined and restricted environments.