INTRODUCTION A national report by the Ofﬁce of Juvenile Justice and Delinquency Prevention (1) found that 9% of U.S. high school students had carried a weapon to school within the previous 30 days. Furthermore, 44% of crime guns traced back to their owners belonged to individuals younger than 25, and 11% of the crime guns belonged to juveniles younger than 17. In 1997, 1400 homicides involved a juvenile offender, and this ﬁgure is probably an underestimate. These data clearly
indicate that aggression and violence among children and adolescents is a leading public health concern.