Research from both simulated and actual jurors has demonstrated that the defendant's emotional display can influence legal decisions. The purpose of this paper is to review the evidence regarding the influence of the defendant's emotional display, and to consider the potential role of suspect and defendant emotion in wrongful convictions. It is possible that the lack of “appropriate” emotion during questioning or interrogation may lead investigators to create a mind-set that the suspect is the guilty party; as a result, they may be less inclined to investigate other leads. During a trial, the defendant's perceived level of emotion can potentially mislead jurors (e.g. a defendant displaying a low level of emotion leading people to believe, inappropriately, that he is guilty). After a review of the pertinent literature and examples of relevant cases, reasons are provided regarding why one's emotional display may be of limited diagnostic value. Future research ideas are proposed in an effort to determine more definitively the impact of the emotional display of the accused on legal decisions. Copyright © 2009 John Wiley & Sons, Ltd.