Offenders placed in hospitals currently receive consideration for release much sooner than those placed in prisons, even though the two groups do not differ significiantly with respect to the characteristics affecting release decisions. The records of a random sample of 253 men convicted by trial courts of manslaughter rather than murder, on grounds of diminished responsibility, showed that it was often a matter of chance whether doctors recommended a hospital order. In addition, nearly all of those sentenced to life imprisonment could easily have received a hospital order if the doctors had used criteria applied in other cases in the sample. Nevertheless, hospital patients began to be released in small numbers quite soon after institutionalization, but almost no prisoner was released before 8 years had passed. This difference is particularly disturbing in view of the trend in recent years to place mentally abnormal homicide offenders in prison rather than in a hospital. The situation makes a mockery of the judicial concept that mentally abnormal people will be detained only as long as necessary in the interests of public safety. The situation makes a mockery of the judicial concept that mentally abnormal people will be detained only as long as necessary in the interests of public safety. The release procedures for mentally abnormal prisoners sentenced to life imprisonment need to change. In addition, a reviewable sentence which would consider dangerousness only is needed. Tables, footnotes, and eight references are provided.