This case study is a description, as well the application, of single-subject design to study human behavior in regard to using best practices in mental health and behavior analysis, to improve the outcomes of victim-offender mediations in a school-based restorative justice program. Two specific interventions were used, acceptance and commitment therapy and behavioral skills training. Two participants were analyzed in this study. The study took place in a public school setting. Single-subject design was used to evaluate the results of the study using ABAB reversals and changing criterion designs. Results suggest that acceptance and commitment therapy can in fact be used to improve the outcomes mediations and that the acceptance and commitment therapy intervention is responsible for the positive behavior changes in the two participants of this study. This article also contains step-by-step instructions on how to conduct the study. A classroom discussion and broader context on when to use find research design versus another concludes the article.