The task force, known as JUDGE (Jurisdictions Unified for Drug Gang Enforcement) targeted juveniles for strict enforcement of probation conditions and identification of possible targets not yet on probation. JUDGE was implemented according to the objectives developed for police and probation components, with vertical prosecution a cornerstone of the approach. For the impact assessment, researchers examined a sample of youth before and after JUDGE intervention. Findings showed that targeted youth were arrested with similar frequency after JUDGE intervention but that the nature of charges differed since there were fewer drug violations. Most cases were prosecuted vertically and reached disposition in a timely manner. JUDGE targets spent a great deal of time in custody and were intensively supervised, with probation violations swiftly acted on by JUDGE staff. An examination of target records several years later revealed that over half were still actively involved in the criminal justice system. Overall, however, the evaluation demonstrated certain benefits and advantages of a multi-agency task force approach and identified features that enhanced effectiveness and credibility. The authors conclude that JUDGE can serve as a model for other jurisdiction seeking to develop cooperative efforts among criminal justice agencies. A case tracking form is appended. 12 references and 29 tables