A total of 90 percent had had psychiatric hospitalization; 92 percent had prior arrest records, with 75 percent of these for felonies. Four-fifths exhibited severe, overt psychopathology. More than three-fourths met the criteria for involuntary hospitalization. When arrested, more than one-third were transients, and only 12 percent were employed. Thus, this population was characterized by extensive experience with both the criminal justice and mental health systems, severe acute and chronic mental illness, and poor functioning. More than half were currently charged with felonies and 39 percent with violent crimes. Attempts were also made to determine why these inmates had been arrested rather than hospitalized, and whether there had been 'criminalization' of the mentally ill. More emphasis is needed on ongoing involuntary treatment for this population. Study data and 26 references are supplied. (Author abstract modified)