Policies of deinstitutionalization, together with a general tightening of civil commitment laws and inadequate funding for community-based programs, have resulted in an increase of mentally ill people on the streets. Growing numbers of former mental patients and individuals whose bizarre behavior might have landed them in a state hospital bed a few years ago are now being arrested and ending up in jail. Four key areas—deinstitutionalization, police decision making, decline of mental health programs, and criminal histories of mental patients—are examined with respect to the shifting of mentally disordered persons from the mental health system to the criminal justice system.