APPROXIMATELY 100 APPARENTLY HABITUAL CRIMINAL OPERATORS PRESENTLY BEING STUDIED BY THE GLASGOW UNIVERSITY CRIMINOLOGICAL RESEARCH UNIT ARE THE SUBJECTS OF THIS PAPER. THEY REPRESENT APPROXIMATELY TWO-THIRDS OF A GROUP OF PERSONS UNDER FAIRLY CONTINUOUS SURVEILLANCE BY DETECTIVE FORCES. MURDEROUS VIOLENCE IS CONSIDERED MARKEDLY UNTYPICAL OF THIS GROUP, BASED ON AN EXAMINATION OF POLICE RECORDS. THEY ARE VIEWED, WITH TWO OR THREE EXCEPTIONS, AS RATIONALLY MOTIVATED PROPERTY CRIMINALS. FOR THESE REPRESENTATIVE MEMBERS OF A CRIMINAL SUBCULTURE, VIOLENCE IS CONSIDERED INSTRUMENTAL, TIGHTLY CONTROLLED, AND KEPT TO A MINIMUM. STATISTICS INDICATE THAT RECORDED SERIOUS VIOLENCE IN THE CITIES WHERE THE SUBJECTS RESIDE IS DERIVED FROM OTHER SOURCES. INFORMATION ON DEGREES OF VIOLENCE WAS AVAILABLE FOR 100 OUT OF THE GROUP OF 110. FORTY-FIVE ARE INDICATED TO BE NONVIOLENT, AND A FURTHER THIRTY SHOW VIOLENCE ONLY TO A MODERATE DEGREE. INFORMATION FOR PATTERNS OF VIOLENCE FOR 54 OF THE 55 'VIOLENTS' SHOWS THAT IT IS DISPLAYED IN TRANSACTIONS WITH MEMBERS OF THE CRIMINAL SUBCULTURE OR DIRECTED AGAINST ACQUAINTANCES AND FAMILY MEMBERS OF THE OFFENDERS. WHILE THE STATISTICAL ASSESSMENT OF THE INDIVIDUAL RECORDS OF THE SUBJECTS INDICATES A PATTERN OF 'LOW-KEY' VIOLENCE, IT IS NOTED THAT THE STUDY UNDERRATES THE IMPORTANCE AND DEGREE OF DANGEROUSNESS OF VIOLENCE IN THE CRIMINAL SUBCULTURE WHICH SUSTAINS THE SUBJECTS. IT IS BELIEVED, HOWEVER, THAT THE CRIMINAL SUBCULTURE ITSELF COULD NOT BE MAINTAINED WITHOUT THE THREAT OR EMPLOYMENT OF VIOLENCE AS THE ULTIMATE MEANS OF INTIMIDATION. IT IS POINTED OUT THAT THIS SUBCULTURAL USE OF VIOLENCE AS A MEANS OF INTIMIDATION IS NOT EASILY QUANTIFIABLE WITH STATISTICS. A SOCIOLOGICAL ASSESSMENT OF THE CONTINUING DYNAMICS OF RATIONAL-ECONOMIC CRIME AND ITS SOURCES IN THE SOCIAL STRUCTURE IS RECOMMENDED. AN APPENDIX IS INCLUDED WHICH EXAMINES THE INCREASE IN SCOTLAND OF SERIOUS VIOLENT CRIME. THE DATA USED IN THE STUDY ARE INCLUDED. (RCB)