THE DANGEROUS OFFENDER IS DEFINED AS THE REPETITIVELY VIOLENT CRIMINAL WHO HAS COMMITTED OR ATTEMPTED TO COMMIT HOMICIDE, FORCIBLE RAPE, ROBBERY, OR ASSAULT MORE THAN ONCE. THE HISTORY OF THE CONCEPT OF DANGEROUSNESS IS TRACED TOGETHER WITH ITS RELATIONSHIPS AND DEPENDENCE ON SOCIAL POWER, ON ECONOMIC CONDITIONS AND CLASS, AND MORE RECENTLY ON VARIOUS PERSONAL ATTRIBUTES. THIS METAMORPHOSIS HAS INVERTED THE IDEA COMPLETELY. THE DANGEROUS WERE ONCE THE POWERFUL SINCE THEY CONTROLLED THE DESTINIES OF ALL WHO SERVED THEM. NOW, THE DANGEROUS ARE MEMBERS OF THE UNDERCLASS -- FEARED NOT BECAUSE OF THEIR POWER, BUT BECAUSE OF THE LACK OF IT. THIS REVERSAL IN THE CONCEPTION OF THE PROBLEM ILLUSTRATES NOT ONLY THE VAST CULTURAL SHIFTS IN SOCIAL HISTORY, BUT ALSO THE IRRESPONSIBILITY THAT CHARACTERIZES CERTAIN SOCIAL RELATIONS AT EVERY AGE. THE THEORIES OF VARIOUS SCHOOLS (SOCIAL DARWINISTS, PHRENOLOGISTS, HEREDITARIANS) AS THEY RELATE TO THE UNDERCLASS ARE DISCUSSED, AS ARE THE RESEARCH EXPERIMENTS OF GENETICISTS, NEUROLOGISTS AND PSYCHOSURGEONS, AND DRUG THERAPISTS. THE DIFFICULTY THAT THE MEDICAL AND SOCIAL SCIENCES HAVE HAD IN TRACING THE CAUSES OF DANGEROUSNESS IS PARALLELED BY THE DIFFICULTY IN ISOLATING SUCH TYPES FOR CLINICAL DESCRIPTION. AT THE HEART OF THE CLINICAL PERSPECTIVE ON DANGEROUSNESS IS THE PSYCHOPATHIC, SOCIOPATHIC, OR ANTISOCIAL PERSONALITY. DIAGNOSTIC SIGNS AND BEHAVIOR TRAITS ASSOCIATED WITH THE SOCIOPATHIC PERSONALITY ARE ENUMERATED, AS ARE EIGHT PHYSIOLOGICAL CORRELATES HAVING TO DO WITH SUCH DYSFUNCTIONS AS ABNORMAL ELECTROENCEPHALOGRAPHIC PATTERNS. THE LEGAL CONCEPT OF DANGEROUSNESS IS ALSO CONFUSED. ONE OF THE MOST PERSISTENT CONFLICTS REVOLVES AROUND THE LEGAL DEFINITION OF CRIMINAL RESPONSIBILITY AND HOW MENTAL DISORDERS IMPINGE UPON IT. VARIOUS STATUTES HAVE BEEN ENACTED WHICH ADDRESS THE PROBLEM OF DANGEROUSNESS, SPECIFICALLY THE HABITUAL CRIMINAL AND SEX PSYCHOPATH LAWS. THE HISTORICAL BACKGROUND AND CHARACTERISTICS OF THESE STATUTES ARE REVIEWED, AND A CRITIQUE OF THESE AND OTHER DANGEROUS PERSON LAWS IS OFFERED. THE AUTHOR CONCLUDES THAT HOWEVER WELL INTENTIONED, THESE LAWS WERE INADEQUATE CONCEPTUALLY AND PROCEDURALLY. A POSTSCRIPT TO THE REPORT MAINTAINS THAT THERE IS LITTLE PROSPECT OF PREDICTING THE COMMISSION OF A VIOLENT CRIME, AND THAT NEITHER STATISTICAL OR CLINICAL METHODS HAVE SO FAR BEEN EFFECTIVE. (AUTHOR ABSTRACT MODIFIED--DJM)