With the passing of the Gun Free School Act of 1994, the 1990s bore witness to the birth of zero-tolerance policies. During the remainder of that decade, several school shootings occurred that solidified zero-tolerance in schools across the United States. With the possibility of threats constantly increasing, school personnel having a thorough understanding of these policies is critical. In this article, the authors analyze the theoretical, empirical, and legal underpinnings of zero-tolerance weapons policies, then argue that these policies are theoretically unsound, are empirically unsupported, and fall prey to several legal critiques. Last, the authors offer recommendations for principals and teachers that would address problems with mens rea and show the value of using threat assessment tools. Published by arrangement with Taylor and Francis.