The United States Supreme Court decision in Clark v. Arizona has become a fundamental part of the landscape concerning the insanity defense and, as a result, has greatly impacted the general use of mental health evidence. In particular, Clark and its progeny have effectively narrowed the scope and significance of mental health evidence used at criminal trials for the state of Arizona and many other states which follow a similar model. This has the net effect of limiting or even eliminating potential defenses and evidence to be considered as a mitigating factor for mentally ill defendants during the guilt phase of trial. Yet, to date, there has not been a study which has examined the impact of Clark on how courts handle mental health evidence or the insanity defense. This dissertation seeks to fill the gap in the literature by systematically reviewing all state and federal criminal cases which have cited the Clark decision through January 1, 2023. During the study period 175 cases were examined using a mixed methods research design. The results indicate that Clark has created an unworkable standard for courts. Specifically, courts have problems properly applying Clark to evidence regarding behavioral tendencies. The data suggests that when behavioral-tendency evidence is even only somewhat linked to a serious mental illness, courts are categorizing this evidence as diminished capacity evidence and excluding it from being admitted in jurisdictions that do not recognize that defense. In addition, courts have issues properly applying their state’s test for the insanity defense. The results suggest that some courts are erroneously conflating purposeful action with appreciation of the wrongfulness of the act.

Dispatchers are the first point of contact for most citizens seeking police services, as well as the lifeline for officers in the field. Their ability to navigate high-stress situations and obtain information from callers is essential to the successful distribution of police resources. Though central to policing, research on dispatchers is quite limited, including the techniques they use to keep callers and officers calm. De-escalation is also underexplored in policing, but recent evaluations of de-escalation training have shown some promise for applications in the field, and reductions in use of force and citizen injuries. Until this project, the nexus of dispatching and de-escalation has not been explored in a way that provides insight from experts in the field who use a subset of skills and techniques to resolve volatile calls and radio transmissions. Using survey responses and semi-structured interviews with peer-nominated Top Dispatch De-Escalators in Tempe, Arizona, this exploratory, mixed-methods study is the first to provide a nuanced perspective of the ways dispatchers de-escalate elevated callers and officers in the field to resolve incidents peacefully. Results from the general survey indicate that dispatchers act professionally when interacting with citizens, care about callers, and treat them with respect. Communication, staying calm, and patience were ranked as the most important deescalationtactics used in dispatching, with compromise being the lowest. Themes gathered from interviews with Top Dispatch De-Escalators shed light on the qualities embodied by an exceptional de-escalator, including listening and communication skills, transparency, and the ability to regulate emotion. Results also provide insight into the barriers that may prevent de-escalation, and recommendations for police agencies looking to bridge the gap that exists between dispatchers, other department personnel, and the community. Findings shed light on the mental health-de-escalation nexus that exists, and the importance of improving conditions for dispatchers which has direct implications for one’s ability to deescalate. This study is the first to examine front-end de-escalation that occurs on the dispatcher side, revealing a missing link in the overall understanding of de-escalation and highlighting the crucial role of dispatch in reducing the potential for violence between community members and police.