During 1980-1982, The Economic Behavior of Street Opiate Users project recruited 201 subjects in Harlem and interviewed them daily or weekly about their behavior on 33 or more consecutive days. For each day, they provided decailed information about their criminal activities and income, their use, purchase, or sale of drugs, their income from all sources, and their expenditures for all purposes. Over 11,700 person days of economic behavior data have been collected, computerized, and have been analyzed to address questions provided in previous applications. This application requests two years of support to provide new information about how the most seriously criminal street opiate users can be differentiated from the less criminal. Continued analysis of these data will generate significant and policy relevant reports which accomplish the following objectives: 1) To describe lifestyles among street opiate users who are: a) seriously criminal and heavy drug abusers, b) seriously criminal but not heavy drug abusers, c) modestly criminal but heavy drug abusers, and d) neither seriously criminal but heavy drug abusers. 2) To clarify which characteristics of the person and/or the specific offense(s) or dug use patterns can successfully differentiate "intensively criminal" street opiate users from their less criminal counterparts. 3) To specify day-to-day involvements in specific types of crimes -- including robbery, burglary, shoplifting, fraud/cons, prostitution, drug sales, and steering/touting/copping --particularly among those who do these crimes at high rates (specialists) compared with those who do so less regularly or not at all. 4) To present the complex relationships on a day-by-day basis between criminal activity and consumption of heroin, methadone, cocaine, and alcohol among street opiate users. 5) To provide careful documentation about the criminal returns (income) and social costs of street opiate users which might be reduced if various treatment and/or correctional alternatives were provided. 6) To examine the probability that specific offenses will be repeated in the near future.