Rodrigo dos Santos, 16, was speeding downhill on a motorcycle in Rio de Janeiro, a knapsack packed with marijuana, cocaine and pellets of crack on his back, when two police officers raised their rifles at him.The teenager sped by, his friend sitting behind him, clutching his waist. But within seconds, they toppled over in a barrage of 38 bullets fired by the police.

Rodrigo died on the way to the hospital, bleeding from a gunshot wound in his arm — and three in his back. The police never claimed he was armed, and one of the officers involved, Sergeant Sergio Britto, was still on duty despite being on trial for murder, accused of shooting another man in the neck at close range.