In Miami-Dade County, Fla. roughly 9.1 percent of the population (more than 240,000 individuals) experience serious mental illnesses (SMI; e.g., schizophrenia, bipolar disorder, major depression), yet fewer than 13 percent of these individuals receive care in the public mental health system. As a result, law enforcement and correctional officers have increasingly become the lone responders to people in crisis: an estimated 15,000 people in need of mental health treatment are arrested each year in Miami-Dade County, primarily for misdemeanors and low-level felonies. Recognizing the opportunity to do better, the Eleventh Judicial Circuit Criminal Mental Health Project (CMHP) was established to divert people with SMI or co-occurring SMI and substance use disorders from the criminal justice system into community-based treatment and support services.