Bullet casings littered the floor of Pavilion Nine. The riot began on October 2, 1992, inside the Carandiru Penitentiary, a facility built for 1,600 men that held 7,300. Inmates fought among themselves, and prison officials, losing control, called in the Military Police of São Paulo state. Colonel Ubiratan Guimarães commanded the operation.
At approximately 3 p.m., over 300 officers entered the prison. They claimed they faced armed resistance. For the next four hours, they cleared the prison block by block. The official report stated 111 prisoners died. Autopsies later showed most victims were shot at close range, many in the head or chest, often in their cells. One police officer suffered a minor injury. The action was framed as restoring order, but the evidence depicted an execution.
The massacre laid bare the Brazilian state's doctrine for handling the marginalized. It was not an aberration but a policy enacted with precision. Colonel Guimarães was initially convicted of homicide in 2001, but the conviction was overturned on a technicality in 2006. The prison complex, a symbol of this brutality, was demolished in 2002.
Carandiru became a foundational reference for human rights groups in Brazil. It demonstrated that the most severe violence could occur within state institutions, documented yet legally unpunished. The event directly influenced later prison reforms in theory, though overcrowding and violence persisted. The number 111 ceased to be a statistic and became a benchmark for state-sanctioned killing.