This research proposes to implement and evaluate the use of a Lethality Assessment protocol and intervention with 6 police departments in Oklahoma, a state where a substantial proportion of IPV victims are Native American. The intervention consists of 2 components: a brief Lethality Assessment, conducted by police at the scene of an IPV incident, designed to determine whether the victim is at high risk for homicide and, if so, immediate coordination with local social service providers. A nonequivalent groups quasi-experimental design is proposed to examine the effectiveness of a Lethality Assessment Intervention (LAI) at decreasing violence and increasing help seeking behaviors for victims of IPV. This research has four aims. The Evaluation Aim will examine the effectiveness of the Lethality Assessment Intervention (LAI) at decreasing the rates of repeat, lethal and near lethal violence, and increasing the rates of help seeking behaviors among victims of IPV. The Validation Aim will assess the predictive and concurrent validity of the Lethality Assessment (LA), which is a shortened version of the Danger Assessment (DA). The Implementation Fidelity Aim will assess the fidelity of the implementation of the Lethality Assessment protocol with the appropriate high risk victims. Finally, the Satisfaction Aim will assess victim satisfaction with the police response and the Lethality Assessment Intervention. This research will introduce nationally a combined criminal justice and social service intervention that can be implemented in most jurisdictions throughout the US affecting both policy and practice responses to the problem of IPV.