Low-level, non-violent offenders, who constitute the vast majority of those with mental illness in our justice system, incarceration is expensive and inappropriate. Many are jailed for offenses such as trespassing, disorderly conduct, loitering or disturbing the peace — offenses often precipitated by their underlying illness.
Yet research shows that with treatment, most low-level offenders with mental illness can return to productive lives and remain crime-free. Diversion into treatment can address the underlying conditions that may have led to their inappropriate and criminal behavior.
http://www.governing.com/blogs/bfc/col-savings-diverting-mentally-ill-jail.html
