An overreliance on truth-detection devices and misunderstandings about the dynamics of sexual violence can correlate with a belief that their use with victims of sexual violence is the best method to conduct complete investigations even though such methods would never be entertained for victims of other types of crimes. This is alarming not only because the results of such tests are unreliable, but the very use of truth-detection devices with victims of sexual violence can do more harm to the victim and frustrate the pursuit of justice. While the utility of truth-detection tests for enticing suspects to agree to be interviewed has long been recognized, there is less appreciation that their use with victims of sexual violence is clearly irreconcilable with trauma-informed interviewing techniques designed to elicit victims’ fullest recollections of events while avoiding further harm. This article provides a brief overview on the his- tory and modern forms of truth-detection devices and discusses how the earliest concerns about their reliability and limitations continue to be valid today. It will discuss why truth-detection devices are inappropriate and how, in many jurisdictions, they are prohibited from being used when interviewing victims of sexual violence. Despite the reliability concerns, it will also be discussed how truth-detection devices remain a potentially useful tool during questioning of suspects.