Blood evidence interpretation has transitioned from a largely observational art to a multidisciplinary science that integrates biology, mathematics, fluid dynamics, and genomics. Once limited to basic visual assessments, bloodstain pattern analysis (BPA) has matured into a rigorous field supported by experimental validation, standardized protocols, and advanced technology. This chapter provides a comprehensive review of BPA’s evolution, scientific foundations, and its integration with modern DNA profiling techniques, including next-generation sequencing (NGS) and forensic genealogy. To demonstrate its practical application, we examine ten landmark case studies showcasing BPA’s ability to reconstruct events, expose false narratives, solve decades-old cold cases, and even overturn wrongful convictions. These cases illustrate the powerful narrative value of blood evidence, which uniquely combines spatial reconstruction with genetic identification. The discussion emphasizes how BPA and DNA interpretation are increasingly interdependent, highlighting innovations such as probabilistic genotyping, digital scene modeling, and artificial intelligence–driven classification. Legal and ethical considerations, including the privacy implications of forensic genealogy and the dangers of expert bias, are also examined. As forensic science undergoes continuous transformation, BPA remains one of its most compelling tools—offering investigators not only proof of identity but also a scientific narrative of crime scenes that withstands judicial scrutiny. This article underscores the importance of rigorous training, certification, and peer review to ensure that blood evidence interpretation continues to advance justice and maintain public confidence.