Based on the subjects official legal status, related narcotics testing requirements, and their self-reported perceptions of criminal justice system coercion, they were categorized into high, moderate, and low legal coercion groups. Those who entered the treatment program through legal channels had slightly higher rates of serious property offenses and higher proportions of time incarcerated and under legal supervision. They did not, however, differ from voluntary entrants in overall criminal behavior during pretreatment periods. During the treatment all groups showed substantial improvement in level of narcotics use, although after treatment there was some regression. 3 notes, 7 tables, 23 references. (Author abstract modified)