THE DATA DISCUSSED CAME FROM A SELF-REPORT SURVEY OF 624 MALE FELON INMATES OF FIVE CALIFORNIA STATE PRISONS, CONDUCTED DURING THE SUMMER OF 1976. RESPONDENTS TOLD WHAT TYPE OF CRIMES THEY HAD COMMITTED DURING THE 3 YEARS PRECEDING THEIR IMPRISONMENT. THEY ALSO REPORTED ON DRUG USE, ECONOMIC CIRCUMSTANCES, PRIOR CRIMINAL RECORDS, REASONS FOR COMMITTING CRIME, AND PERCEPTIONS OF THE PAYOFFS AND PENALTIES OF DOING CRIME. ESTIMATES WERE DEVELOPED OF THE PROPORTION OF THE CRIMINAL POPULATION WHO COMMIT DIFFERENT TYPES OF CRIME AND THE FREQUENCY OF CRIME COMMISSIONS. A GROUP OF OFFENDERS WAS IDENTIFIED WHO SHARED COMMON CHARACTERISTICS AND HAD COMMITTED A LARGE PROPORTION OF THE CRIME REPORTED BY THE SURVEY SAMPLE. THEY HAD BEGUN COMMITTING SERIOUS CRIMES AT AN EARLY AGE AND PERCEIVED THEMSELVES AS PROFICIENT CRIMINALS IN A NUMBER OF WAYS. THEY TENDED TO BE HEDONISTIC AND VIEWED CRIME AS THE MOST EFFECTIVE WAY TO OBTAIN THE GOOD LIFE. THERE WAS LITTLE CONCERN ABOUT ANY PAINFUL CONSEQUENCES AS A RESULT OF THEIR CRIMINAL LIFE, AND THEY EXPECTED TO RETURN TO CRIME AFTER PRISON. THIS TYPE OF OFFENDER, WHICH COMPOSED 25 PERCENT OF THE SAMPLE, HAD COMMITTED 58 PERCENT OF ALL ARMED ROBBERIES REPORTED BY THE ENTIRE SAMPLE, 65 PERCENT OF ALL BURGLARIES, 60 PERCENT OF ALL AUTO THEFTS, AND 46 PERCENT OF ALL ASSAULTS. ALTHOUGH THE STUDY PROVIDES VALUABLE NEW INFORMATION, ITS LIMITED SCOPE AND INADEQUATE METHODOLOGY MAKE THE CONCLUSIONS TENTATIVE.