On Oct. 2, 1992, riot police from the Brazilian police force forcibly put down a riot in the Carandiru Detention Center, killing 111 in Brazil's worst prison massacre. In cell block 9, a fight broke out between two prisoners from rival gangs over exercise space. The fight resulted in the hospitalization of one prisoner following a blow to the head with a wooden club. In response to the conflict, prisoners broke into the exercise yard and a riot ensued. By 2 pm, the prisoner's controlled the area, though no hostages were taken and no escape attempts were made.
Prison officials notified the Commander of the Metropolitan Sao Paulo Police, Col. Ubiratan Guimaraes, of the situation. Col. Guimaraes called for reinforcements from the Brazilian police force and by roughly 3 pm, prison officials handed control of the situation over to the Brazilian police force. Police officers were stationed outside the prison walls by 3:30 pm.
A government account later said that at the time, prisoners displayed their willingness to negotiate by throwing their weapons from windows and hanging truce flags from the prison walls. Brazilian forces , who were not in uniform , stormed cell block 9 and invaded the area under orders from Col. Guimaraes.
Eyewitness accounts state that prisoners ran for cover after Brazilian police entered the area. The police force quickly overran the ground floor of the cell block and allegedly shot several prisoners in the head and chest as they attempted to flee. Experts and witnesses later testified that many prisoners were shot execution style as they hid behind mattresses. In the end, police fired over 500 rounds, killing 103 prisoners. 8 prisoners later died from stab wounds. No police officers were killed.
Col. Guimaraes was tried and convicted for murder of 102 of the inmates. A Brazilian court sentenced him to 632 years in prison. On appeals, however, the court overturned the ruling. Col. Guimaraes claimed his forces were acting in self defense. His defense team argued that he was only following orders during the riot. This same defense was declared illegitimate almost 50 years earlier during the Nuremberg Trials examining the atrocities committed by Nazi Germany.
