The homicide rate in Rio de Janeiro tripled in the last 15 years and public concern grew apace. The press, prominent civic leaders, and politicians focused particularly on violence related to criminal gangs and drug trafficking. Unfortu-nately, law enforcement efforts to control crime relied on flagrant and numerous human rights abuses. This report documents instances of police brutality, including two massacres in which 27 residents of one of Rio's hillside slums were killed. We also document the human rights violations that accompanied the largest assault to date on Rio's drug gangs, Operation Rio, from November 1994 to mid-1995, which included torture, arbitrary detentions and warrantless searches and at least one unnecessary use of lethal force.