Data were collected from police records and hospitals where subjects had been treated. Of the 36 percent who recidivated, 7.4 percent were again found unfit to stand trial or judged NGRI. While more than 80 percent of the crimes were nonviolent, the others were violent and some were very serious. Of the recidivists, almost 60 percent were sentenced to a penitentiary. Nonviolent criminal activity appeared sooner after discharge than did violent crimes. Comparisons of recidivists with nonrecidivists revealed that offenders were more likely to recidivate who had more convictions of unfitness or insanity, had committed more varied crimes, and were younger at discharge. Two distinct subgroups emerged among the recidivists: career criminals and chronic schizophrenics who had spent most of their adult lives in hospitals or penal institutions. Policy implications of the study's findings are discussed. Tables, graphs, and over 30 references.