This report evaluates the New York City-based Arches Transformative Mentoring program, finding that participation in the program reduces one-year felony reconviction by over two-thirds, and reduces two-year felony reconviction by over half, with especially profound impacts for the youngest program participants. The program's evidence-based curriculum is completed over a 6-12-month period and delivered in a group setting by "credible messengers," direct service professionals with backgrounds similar to the populations they serve.