The Serial podcast became a sensation in late 2014, drawing millions of listeners to the true crime podcast genre and influencing the growth of a population of legacy podcasts. This chapter uses case study examples from the post-Serial phenomenon, exploring how these podcasts built community, legitimacy, and leveraged their popularity for actual change in U.S. cases. Five podcasts are included in this analysis: Undisclosed, Truth & Justice, Up & Vanished, Breakdown, and In the Dark. These podcasts represent a cross-section of the producers in this niche—amateur investigators, criminal justice system insiders, and news professionals. Each podcast examined has been involved with ongoing cases, including wrongful convictions and missing persons’ cases, and offers examples of both the power and pitfalls of the exploding true crime podcast universe. Together, these cases offer a snapshot of this ecosystem and encourage continued exploration of the potential of true crime entertainment for systemic change.

Additionally, the growth of this “population”—an ecological term for organizations with similar forms and resource requirements—can be examined from both organizational ecology and social movements theory paradigms. That is, these podcasts exist in an ecological space, a “niche,” conducive to resource acquisition, competitive and collaborative relationships, and audience growth. From an ecological perspective, true crime podcasting is a quickly growing industry, expanding into a world of multimedia collaborations, podcast superstars, and massive fan communities. At the same time, these true crime podcasts focus on criminal justice reform, wrongful convictions, cold cases, advocating against injustice, and also work within social movement paradigms. These justice-centered true crime podcasts use norms from both investigative journalism and classic true crime entertainment to educate their audience, create collective identity, and mobilize resources for social and institutional change. At the same time, these podcasts face criticism regarding ethical reporting and the far-too-often-exploitative nature of the true crime genre. Together, the dual theoretical perspectives of ecology and social movement theory help us to understand the motivations and challenges faced by these new true crime superstars and justice advocates as the podcasting industry evolves.