School safety is important to learning and to well being (Allen, Cornell, Lorek, & Sheras, 2008; American Psychological Association [APA] Zero Tolerance Task Force, 2008; Robers, Zhang, Truman, Snyder, 2010). Aggression in schools has long been a problem. Although barricaded captive events and rampage or targeted shootings are infrequent occurrences (Borum, Cornell, Modzeleski, & Jimerson, 2010; Daniels, Royster, Vecchi, & Pshenishy, 2010a), their long-term impact on schools, individuals, and families can be signižcant. In addition to school preparedness for the possibility of such events is the need for early preventive interventions that reduce the likelihood of their occurrence. Because some of the traits, circumstances, and conditions associated with the individuals who commit such events are also associated with other youth difžculties, engaging in early interventions such as those presented in the second half of this book may prevent a number of youth and later adult problems including aggression.