The study is organized by viewing the problems in terms of the criminal history of the drug addict. The three major areas discussed here include the temporal sequence of criminal involvement, the extent and types of crime committed while addicted, and the impact of treatment on criminal behavior. The findings of this analysis show that most current heroin addicts have substantial criminal records prior to the first time they used opiates. There is no reason to believe that addiction is a causal factor in increasing criminality among those drug users who were criminals prior to their addiction; however, engaging in criminal behavior seems to increase the probability of becoming addicted to drugs. Most of the evidence suggests that addicts primarily commit crimes that are financially rewarding, whether or not they are also violent. 2 notes and 125 references