Severe, compared to mild, harm results in harsher punishment. According to the model of people as intuitive prosecutors, the severity effect is a deterrence message. The authors tested this hypothesis in two studies in Singapore. In Study 1, participants learnt about the severity of harm arising from an accidental or intentional act, and expressed anger, made attributions, assigned blame, recommended compensation by and imprisonment of the offender, and indicated the degree to which they were guided by the punishment goals of deterrence and retribution. As hypothesized, the prosecutorial mindset was multidimensional, and the deterrence goal mediated the severity effect on punishment. In Study 2, the severity effect held when the punishment goal was unspecified but not when it was experimentally specified as deterrence.