DATA WAS GATHERED FROM COURT RECORDS, PSYCHIATRIC REPORTS, POLICE COMPLAINTS, AND THE RECORDS, OF ALL MALES CONVICTED OF A SEX OFFENSE IN PHILADELPHIA FROM 1966-1970 JUDGES WERE ALSO INTERVIEWED. CIRCUMSTANCES IN WHICH PRESENTENCE PSYCHIATRIC REPORTS WERE REQUESTED AND EXAMINED. OFFENDERS FOR WHOM REPORTS WERE ORDERED, AND THOSE SENTENCED WITHOUT REPORTS, WERE COMPARED. VARIATIONS IN THE USE OF PSYCHIATRIC REPORTS FROM ONE JUDGE TO ANOTHER, AND THE BEHAVIOR OF A PSYCHIATRIST IN MAKING A PROGNOSIS, WERE CONSIDERED. THE SERIOUSNESS OF THE OFFENSE, PREVIOUS RECORD, AND THE AGE OF THE VICTIMS WERE AMONG FACTORS SIGNIFICANTLY RELATED TO ORDERING A REPORT. THE PRESENCE OF A REPORT DID NOT GENERALLY AFFECT THE TYPE OR LENGTH OF THE SENTENCE. THE RECOMMENDATIONS OF THE PSYCHIATRISTS AND THE JUDGES SENTENCES CORRESPONDED IN ONLY HALF OF THE CASES, A FINDING LOWER THAN THAT EXPECTED FROM RESEARCH WITH PROBATION REPORTS AND SOME SCHOLARLY OPINION. IMPLICATIONS OF THE STUDY ARE PRESENTED, AND LIMITING FACTORS AFFECTING THE JUDGES' POTENTIAL USE OF PSYCHIATRIC REPORTS ARE DISCUSSED. (AUTHOR ABSTRACT MODIFIED--DAG)