This essay looks at the events surrounding a mercury spill in Choropampa, Peru and the responses of corporate actors, government representatives, and local residents. Legal proceedings and expert knowledge masked corporate negligence and the complicity of the state. Meanwhile, local residents complained of ongoing illnesses but could not substantiate their claims with laboratory test results. The body became a political battleground and the perpetuation of people’s ailments was one way to substantiate their claims for justice. This essay uses the mercury spill case to argue that disputes between corporations and communities are often based on disagreements over what counts as evidence and whose knowledge counts as legitimate.