On a sweltering March evening in 2018 Marielle Franco was shot dead. Rio de Janeiro is a routinely violent place but this was different. Marielle was a rising star of the city's political scene and was hit four times in the head by a professional hitman. Elected the same year, President Bolsonaro, an enthusiast for torture, murder and the worst excesses of the country's 1964-1984 military dictatorship, subsequently declared war on the country's institutions...