This publication is from a series that addresses how law enforcement responds to people with mental illnesses. This report is divided into two sections: Section 1 is Step by Step: The Program Design Process which addresses the seven steps needed to shape a program to best address a jurisdiction's distinct resources and needs. This section establishes the planning process for policymakers and practitioners interested in learning how to design or revise a program, whether it is a CIT, a co-responder model, or some combination or variation of these models. It takes into full account the specific factors that drive their jurisdiction's problems associated with law enforcement interactions among people who have mental illnesses. Section 2 is From the Field: Program Design in Action which provides two overview chartsone about problems that affect program design and the other about jurisdiction characteristics that can affect initiative plans. It also provides specific examples that illustrate how program design processes are translated into activities in the field, drawing on information provided during interviews and site visits. Also described are how program elements are tailored to a jurisdiction's problems and specific characteristics when implemented. This section will help individuals interested in learning more about how other agencies throughout the country have navigated the program design process to develop these evolving initiatives. Appendixes A-C