We study a Force-down/Shoot-down intervention in Brazil that led cocaine traffickers to shift from air to river routes. Using data on cocaine production, homicides, and the network of rivers in the Amazon, we provide evidence that violence increased in municipalities along river routes originating from Andean producing countries after the policy. We also show that, during the same period, violence in these municipalities became more responsive to cocaine production in origin countries. We document an instance of crime displacement over the three-dimensional space, involving sophisticated adaptations from criminals regarding transportation technologies, with dramatic side-effects for local populations.