Sao Paulo - Police violence in Brazil climbed rapidly in the first nine months of the year, when the civil and military police killed 478 people, 25.4 per cent more than in the first nine months of 1998, according to a government study released yesterday. During the same period, 91 police officers were killed. The mortality rate for the police rose 250 per cent for civil authorities and 25 per cent for the military, according to the study. The majority of those officers were killed while working second jobs, usually as security guards.