Is the basis of criminality an act that causes harm, or an act undertaken with the belief that one will cause harm? The present study takes a cognitive neuroscience approach to investigating how information about an agent's beliefs and an action's consequences contribute to moral judgment. We build on prior developmental evidence showing that these factors contribute differentially to the young child's moral judgments coupled with neurobiological evidence suggesting a role for the right temporoparietal junction (RTPJ) in belief attribution. Participants read vignettes in a 2 × 2 design: protagonists produced either a negative or neutral outcome based on the belief that they were causing the negative outcome ("negative" belief) or the neutral outcome ("neutral" belief). The RTPJ showed significant activation above baseline for all four conditions but was modulated by an interaction between belief and outcome. Specifically, the RTPJ response was highest for cases of attempted harm, where protagonists were condemned for actions that they believed would cause harm to others, even though the harm did not occur. The results not only suggest a general role for belief attribution during moral judgment, but also add detail to our understanding of the interaction between these processes at both the neural and behavioral levels.