Key findings from this study on outcomes for people with mental illnesses involved in New York City's criminal court and correction systems include the following: people with mental illnesses booked into the City's Department of Corrections (DOC) had consistently longer lengths of stay, 112 days, compared to individuals without mental illnesses, 61 days; when compared to detainees with no mental illnesses, detainees with mental illnesses were less likely to make bail, 12 percent versus 21 percent, and stayed in jail considerably longer before making bail, 48 days versus 9 days, respectively; individuals diagnosed with serious mental illness had shorter lengths of stay, on average, than those who did not meet the criteria for serious mental illness or those with no mental illness; and individuals with mental illnesses experienced delays in case processing for many reasons, including lack of information on alternatives to incarceration and detention needed by key decisionmakers. Data for this study were obtained from the records for over 48,000 individuals in New York City's adult criminal justice system admitted into the City's DOC in 2008 with a length of stay greater than 3 days. The purpose of the study was to obtain information needed for developing and implementing data-driven strategies for improving the City's response to individuals with mental illnesses who were involved with the criminal justice and correction systems. A set of recommendations was developed for establishing a policy framework for dealing with this population. Figures and endnotes