To deter youth from committing offenses and to punish those who do offend, increasingly stricter codes of conduct have been implemented. Many of these policies are predicated on the idea that once youth begin to engage in antisocial activities they are at increased risk to continue to behave inappropriately. Using meta-analytic techniques, this paper examines the evidence for that belief and several other aspects of the predictive relationship of antisocial and substance-using behaviors on the display of violent or threatening behavior. The paper also assesses the concurrent and predictive relationships of these predictors with violence and specifies the accuracies and errors associated with identifying persons for intervention or prevention to reduce violence based on previous displays of these antisocial behaviors. Figures, references, notes