This dissertation considers how, beginning in 1969, Americans encountered an unprecedented density of cultural material about spectacular murder cases that shaped their lives and their choices. I argue that a collective experience of spectacle murders, which became shared local and national phenomena through new forms of media and a widespread interest in crime prevention, constituted a powerful historical force that remade the political and social possibilities of the late twentieth century. The incredible malleability of these narratives and images depended largely on their appeal to the individual emotions of middle-class white Americans and their sense of safety, space, belonging, and home. Influenced by cultural material about real as well as fictional murders across the state of California, these Americans – many of them women – turned to self-defense, vigilantism, and a demand for increased policing and incarceration rather than embrace collective action that might have addressed the social factors undergirding the problem of violent crime. Through the construction of these national spectacle events, the cultural figure of the “murderer” became a specter for the country’s crime problem as a whole, while the victim came to stand for all that seemed under attack in American life. Anti-crime activists’ intense fear, profound grief, and righteous outrage worked to invest punitive solutions to crime with both a prevailing cultural logic and an irrefutable moral authority. Through television shows, radio programming, the paperback industry, documentary films, and tourist events, the rise of “true crime” similarly imbued murders with an entertainment value that bordered on voyeurism and allowed everyday Americans to participate in a novel project of crime prevention based largely on national myth and imagination. Over the course of the 1970s, 1980s, and 1990s, an investment in solving certain murders at the personal, local, state, and federal levels contributed to – and even produced new forms of – structural violence and inequality while failing to meaningfully reduce interpersonal injury or harm. This dissertation thus explains the centrality of a dual fear of and fascination with murder to the rise of some of America’s most dire social crises: mass incarceration; criminalization; abuses of power within the criminal legal system; the rise of a paramilitarized surveillance and security state; mental health awareness; and consuming mass violence.