who's the thief? The influence of knowledge and experience on early detection of criminal intentions

Our study investigates if people are able to recognize thieves based on their nonverbal behavior prior to committing the crime. We implemented authentic closed-circuit television footage from thefts committed at an international airport into a computer-based test. Five groups of participants (students, police recruits, inexperienced police officers, experienced police officers, and criminal investigators) were studied. The results show that criminals display nonverbal behavior that can be used by observers for early recognition of criminal intentions. In addition, early recognition seems to benefit from knowledge about the criminals' modi operandi (criminal investigators performed best), which renders early recognition teachable and trainable. Further, all participants seem to be biased towards innocence, but this bias was less pronounced in police officers than in students. These findings are discussed in relation to the well-documented truth-bias and investigator-bias in lie detection research as well as taking our measurement method into account