A MURDER COMMITTED BY A PERSON WHO PREVIOUSLY HAD PASSED THROUGH SEVERAL BRITISH PSYCHIATRIC HOSPITALS IS USED TO ILLUSTRATE THE PROBLEMS FACING CRIMINAL JUSTICE OFFICIALS AND PSYCHIATRISTS WHEN DEALING WITH POTENTIALLY DANGEROUS PERSONS. AFTER REVIEWING THE DIFFICULTIES INVOLVED IN DEFINING THE TERM 'PSYCHOPATH,' THE ETIOLOGY OF THE DISORDER IS DISCUSSED. DUE PROCESS CONSTRAINTS ON MENTAL HEALTH PROFESSIONALS TREATING SUCH PERSONS ARE REVIEWED. POLICY STATEMENTS OF THE HOME OFFICE COMMITTEE ON MENTALLY ABNORMAL OFFENDERS, THE NATIONAL ASSOCIATION FOR MENTAL HEALTH, AND THE ROYAL COLLEGE OF PSYCHIATRISTS ARE REVIEWED. THE FOUR FACILITIES IN ENGLAND FOR THE TREATMENT OF SUCH PERSONS ARE DESCRIBED BRIEFLY. THE LACK OF REALLY EFFECTIVE TREATMENT METHODS IS EMPHASIZED. SEVERAL REFORM PROPOSALS ARE REVIEWED. REFERENCES ARE PROVIDED. (GLR)