During the year 135 prisoners were involved in riots from January to June in federal prisons. There were several official complaints of overcrowding in Goiás, Rio de Janeiro, São Paulo, and Minas Gerais states. Summary executions and police violence Police violence is one of the most internationally recognized human rights abuses in Brazil. The problem of urban violence focuses on the perpetual struggle between police and residents of high crime favelas such as the areas portrayed in the film City of God. Police response in many parts of Brazil is extremely violent, including summary execution and torture of suspects. According to Global Justice, in 2003, the police killed 1,195 people in the State of Rio de Janeiro alone. In the same year 45 police officers were killed. It is often reacted to by local communities and trafficking groups with demonstrations and violent resistance, causing escalation and multiplying victims. Unofficial estimates show there are over 3,000 deaths annually from police violence in Brazil, according to Human Rights Watch. There are constant complaints of racism, abuses, torture, executions and disappearances. Not all states record police killings or keep accurate statistics. Reports of killings by Rio de Janeiro police decreased during the year under a new state security strategy. Statistics released by the Rio de Janeiro State Secretariat for Public Security showed 911 persons killed as a result of police confrontations from January through September, a 12 percent decrease over the same period in 2007. The Rio de Janeiro Institute for Public Security reported that police killed an average of four persons per day during 2007. According to a UN report released in September, police clashes resulted in 1,260 civilian deaths in Rio de Janeiro State in 2007. Most of these killings occurred during "acts of resistance," the UN report commented. The São Paulo State Secretariat for Public Security reported that São Paulo state police (civil and military) killed 340 civilians in the state from January to September, compared with 315 during the same period in 2007. Cases involving extrajudicial executions were either under police investigation or before the state courts; observers believed that it could take years to resolve such cases. There were no reports of politically motivated disappearances. However, the Center of Studies of Security and Citizenship estimated that in 2006 approximately 1,940 persons "disappeared"; the center believed many were killed by police. There were no developments in the disappearance cases