Book excerpt: The prevalence of exposure to traumatic events among American children is staggering. It is also well established that violent victimization increases the risk of juvenile delinquency. Nonetheless, the specific pathways by which traumatic life events lead to delinquent activity among youth are not well understood. Because there are a variety of adverse psychological, emotional, and cognitive consequences of trauma, it is important to understand the different ways in which these consequences affect behavior. A potential mechanism of increasing interest to scholars is Posttraumatic Stress Disorder (PTSD). Using the 1995 National Survey of Adolescence, the current research study demonstrates the importance of using a developmental perspective to investigate the mechanisms by which PTSD increases the risk of juvenile delinquency. Exhibiting signs of PTSD at younger ages can have more deleterious effects on a child's life trajectory than developing it later in life. Adolescents who ever developed PTSD are also more at risk of juvenile delinquency, regardless of the developmental period in which they first exhibited signs. In addition, the findings indicate that victimization, witnessing violence, and experiencing other traumatic life events are still strong predictors of juvenile delinquency, even when PTSD is included in the model. Supporting previous research, surrounding oneself with deviant peers also increases youth's chances of criminal behavior. These findings suggest that while PTSD is an important component of a youth's risk of committing a crime, there are other essential conduits that lead traumatized youth towards juvenile delinquency. The current study implies that child welfare, mental health, and juvenile justice systems are intricately intertwined regardless of whether these systems acknowledge their overlapping populations. Encouragingly, there are evidenced-based treatments available that have been shown to effectively reduce PTSD symptoms with lasting results. Until families and child-serving agencies identify these symptoms, however, youth will go untreated.