The largest referral source for adolescents to substance use treatment in the United States is the juvenile justice system. Alcohol and drug use is illegal, and some youth have legal issues because they use or sell alcohol or drugs, but many adolescents also become involved in the juvenile justice system because of poor decisions they make under the influence of alcohol or drugs. It is important to understand the relationship of a treatment to illegal behaviors. A recent study of nearly 1,500 adolescents examined whether A-CRA participation was related to reductions in illegal activities (other than substance use) and juvenile justice system involvement. Findings showed that participation in A-CRA treatment predicted significant decreases in future substance use, which in turn, led to significant reductions in illegal activity and juvenile justice involvement.