Questionnaire surveys were conducted of criminology experts outside the nuclear industry and also of professionals involved in managing nuclear fuel activities. Results show that employee involvement for fissile materials is probable and that either profit or political motivation is likely. Employees involved in thefts of fissile materials are likely to be highly trained and not faced with personal problems. Thefts by organized crime seem unlikely. Experts in management are concerned about theft of fissile materials by foreign groups or nations. Deterrents against fissile material thefts are physical security, stringent accountability, and personnel management. Respondents evaluate the effectiveness of personnel selection for security to be better for fissile materials than for other criminological fields surveyed. (NTIS abstract)