Facing the digitization and intellectualization of crime trends and the transformation of social governance models, forensic science is also in urgent need for transformation and upgrading. Introducing the trinity concept of investigation, prevention, and service into forensic science will facilitate its shift from “criminal investigation” to “social governance.” While strengthening investigative support for combating crime, this concept will enhance the capacity for crime prevention and public service, thereby contributing to the modernization of the national governance system and governance capabilities. This paper introduces the origin and theoretical foundation of the trinity concept of “investigation, prevention, and service”, explores its rationale in forensic science work, examines its practical applications in guiding forensic practices, and proposes actionable pathways for forensic science under this tripartite framework.