The present research sought to investigate the psychological dynamics underlying demonizing, that is, the tendency to see others as personifications of pure evilness. Building on an integrative theoretical framework, it is hypothesized that the extent to which a perpetrator matches prototypical expectations of evilness shapes demonizing responses to offenders particularly when cognitive resources are impaired. In two experiments, participants were asked to memorize either a difficult or an easy telephone number (cognitive load vs. control), and were then asked to evaluate a perpetrator who murdered a young woman (Experiment 1) or who kidnapped a child (Experiment 2). Results revealed that the extent to which the description of the perpetrator was consistent with a prototypical evilness scheme influenced demonizing particularly under conditions of cognitive load. It is concluded that impairment of cognitive resources increases the influence of prototypical evilness on demonizing. © 2010 The Author(s).