UPP officers in Rio de Janeiro

Homicides have fallen 65 percent in the Rio de Janeiro favelas where Police Pacification Units have been installed during four years of the flagship scheme -- an impressive figure, but one that could just indicate a displacement of violence to other regions.

A study by Rio's Public Security Institute (ISP) looked at 22 Rio neighborhoods where Police Pacification Units (UPPs) have been in operation for more than a year. A total of 36 favelas now have UPPs as part of a strategy under which the military enters neighborhoods and occupies them until order is deemed to have been restored, at which point a UPP community policing unit is installed.

The ISP study found that homicides had dropped by 65 percent across the 22 favelas between 2008 and 2012, reported The Rio Times.

However, when the cases were taken individually, results were mixed. In some favelas, no homicides had occurred within the past year, the report said. But residents of other favelas said they had seen no changes in the levels of violence since the UPPs began operating in Rio. Others said their presence had increased tensions due to police abuse.

InSight Crime Analysis

Homicides are the usual measure for success for programs such as this and in that respect, the UPPs are performing well. Another study found there was an average of 60 fewer murders per 100,000 residents in favelas where the UPPs operate.

With 4,030 intentional homicides in 2012 in the state of Rio compared to 5,717 in 2008, according to ISP statistics, there has been a 29.5 percent drop in absolute number of murders for the state, a very impressive drop by any standard.

However, homicides are only one measure. Kidnappings nearly doubled in the state between 2011 and 2012. Concerns have also emerged that the UPPs, rather than stopping the city's criminal activities, may simply be displacing them to other areas. Murders in other parts of Brazil, such as the northeastern states and the southeastern department of Minas Gerais, are on the rise. There have also been reports of gangs moving back into the favelas.

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Meanwhile, the reputation of the UPPs has been damaged by reports of abuses by the officers, as well as criticisms that the program fails to address underlying social needs. That abuse came to the fore in the recent case of a bricklayer who was picked up, tortured and killed by UPP officers.