People make accurate social judgements from minimal information. Although this is believed to be evolutionarily-evolved, accuracy is not universal. This study investigated personality traits’ roles, including psychopathy, in violence perception accuracy and the facial cues used in these perceptions. From two-second glances at faces, two undergraduate samples judged 84 sexual offenders’ violent propensities and completed personality measures. Participants were unable to distinguish violent from less-violent offenders and neither gender was more accurate. Facial cues of masculinity tended to be valid cues. Most general personality characteristics did not contribute to accuracy, however, low honesty-humility (associated with increased psychopathy) contributed to greater accuracy in sample two. Boldness and total psychopathy, measured by the Triarchic Psychopathy Measure, also contributed to increased accuracy for sample two. The results suggest that people use valid and misleading cues in rapid judgments about violence and that the role of psychopathy in threat detection accuracy warrants further investigation.