This study was an outcome evaluation of the Dallas County Judicial Treatment Center (DCJTC), a six-month residential substance abuse treatment (RSAT) facility in Dallas County, Texas. The primary goal of this evaluation was to assess offender recidivism following treatment in this six-month community-based modified therapeutic community for probationers. Secondary goals were to examine change in social functioning over time among probationers mandated to this program, to determine which characteristics at intake and which during-treatment social functioning indicators were predictive of dropping out of treatment early, and to identify which indicators predicted being arrested one to two years after treatment. These goals were accomplished by a comparison of outcomes between treated probationers and an untreated comparison group and by an assessment of the relationships among treatment, social functioning, and recidivism. For both treatment and comparison groups, a criminal records search was performed on the Institutional Division database of the Texas Department of Criminal Justice for all of the study participants for the two years following discharge for treatment or following commitment to probation. In addition to these records, treatment participants were asked to complete a set of data collection forms over their course of treatment. These forms collected information about mental status, background and psychosocial functioning, substance abuse, psychological status, offenders' perceptions of the program and their experiences in treatment, evaluations of counselors, self-evaluations, and counselors' evaluations of clients.