Butner is a research and a mental-health institution and it houses a small general population. Fifty-one percent of the inmates are serving time for a violent offense, and 81 percent have committed a violent offense at some time. The average sentence is 8 years, which is above the average sentence in all Federal institutions. The research population consists of about 150 men selected by computer to meet certain criteria. They are either recidivists, violent offenders, or both. Rehabilitative programs are voluntary. A fixed parole date is intended to get rid of the games inmates play in using pretense at rehabilitation to influence the parole commission. Although participation in specific programs is optional, inmates cannot choose idleness. Every inmate must work a half-day, and the rest of the day may be spent in work or programs of education, vocational training, counseling, or industry. Every inmate establishes an individualized contract of graduated release when he first arrives, such that he knows, for example, when he will be getting his first furlough and when he will be released to a halfway house. A medical model is used only for the mental-health population which is made up primarily of those referred from other institutions. The basic mental-health program is centered in a therapeutic community structure complemented by individual psychiatric attention. Each housing unit is run by a team composed of a unit manager, a case manager, a psychologist, a counselor, an educational representative, and inmate representatives. Twenty-three percent of the staff is female. A question and answer discussion follows the presentation.