Urban discusses the effectiveness of a court-ordered juvenile curfew enforcement program known as Nightwatch. Her questions include: Do juveniles who participate in Nightwatch re-offend less? and If they do re-offend less, why? The Nightwatch program operates using sanctions for non-compliance and rewards for compliance, which predicts that juveniles with a high certainty of punishment for curfew violation will have a low incidence of non-compliance and subsequent offending. Results indicate that juveniles participating in Nightwatch recidivated at significantly lower levels than a comparison group, but not for the reasons expected by court officials. Little support was found for deterrence, but participation in Nightwatch reduced time out of the house and was a significant predictor of subsequent offending.