THE PATUXENT INSTITUTION PROVIDED PSYCHIATRIC AND OTHER SERVICES TO OFFENDERS WHO WERE DESIGNATED DEFECTIVE DELINQUENTS AND COMMITTED INVOLUNTARILY TO THE INSTITUTION TO SERVE INDETERMINATE SENTENCES. ALL CRIMINAL ACTIVITY DURING THE FIRST 3 YEARS AFTER RETURN TO THE COMMUNITY THROUGH PAROLE, SENTENCE EXPIRATION, OR COURT MANDATE WAS ANALYZED FOR EACH OF FIVE RESEARCH GROUPS: (1) ALL PATUXENT INMATES PLACED ON PAROLE STATUS IN 1971 AND 1972; (2) ALL PATUXENT INMATES RELEASED IN 1971 AND 1972 THROUGH REDETERMINATION (OF DEFECTIVE DELINQUENT STATUS) HEARINGS OR LEGAL TECHNICALITIES; (3) ALL INMATES FROM 1964 THROUGH 1972 WHO WERE EVALUATED AT PATUXENT AND FOUND TO BE DEFECTIVELY DELINQUENT BUT NOT COMMITTED TO THE INSTITUTION BY THE COURT; (4) ALL INMATES REFERRED FOR EVALUATION BY PATUXENT STAFF IN 1967 AND FOUND NOT TO BE DEFECTIVELY DELINQUENT; AND (5) A SAMPLE OF 100 INMATES PAROLED IN 1971 AND 1972 FROM MARYLAND CORRECTIONAL FACILITIES. ACCORDING TO THE ANALYSIS, OFFENDERS WHO COMPLETED THE PATUXENT PROGRAM AND WERE PAROLED CAME TO THE INSTITUTION WITH LONGER AND MORE SEVERE ARREST RECORDS THAN ANY OF THE OTHER GROUPS BUT AFTER RELEASE WERE ARRESTED APPROXIMATELY AS OFTEN AS THE OTHER GROUPS. PATUXENT APPEARS TO REDUCE THE REARREST RATES FOR HARDCORE OFFENDERS TO THE LEVEL OF OTHER OFFENDER GROUPS. IT SHOULD BE KEPT IN MIND, HOWEVER, THAT THE RELATIVELY LONGER INCAPACITATION OF PATUXENT PAROLEES RETURNS THEM TO THE COMMUNITY AT AN AVERAGE AGE OF 33 COMPARED TO AGE 27 FOR THE OTHER STUDY GROUPS. THE PATUXENT OFFENDERS, THEREFORE, WERE INCAPACITATED AT A TIME WHEN STATISTICALLY THEY WOULD BE AT A VERY HIGH RISK OF REARREST. THE RECIDIVISM DATA SHOULD ALSO BE CONSIDERED IN LIGHT OF THE COSTS OF THE PATUXENT PROGRAM TO THE STATE AND TO THE OFFENDER. SUPPORTING DATA AND A BIBLIOGRAPHY ARE INCLUDED. (LKM)