Sexual assault victims have long faced unwarranted skepticism from friends and family members, as well as responding professionals. In this Training Bulletin, we document examples of this historical bias and examine a few measures that have been taken to help ameliorate it. In particular, we focus on the Start by Believing philosophy and examine its relevance for victim and suspect interviews. Our goal is to inform criminal justice professionals and others about what this philosophy does – and does not – say about how to approach sexual assault cases, including interviews with victims, suspects, and witnesses. Ultimately, we emphasize that Start by Believing is an approach to conducting thorough, professional, and unbiased investigations.