On April 20, 1999 at Columbine High School in Littleton, Colorado, two heavily armed students killed twelve students and one teacher and seriously wounded nearly two dozen others before killing themselves. The following month in Conyers, Georgia, a 15-year-old student wounded six other students. In December, an Oklahoma middle-school student took a semiautomatic handgun to school and wounded five students. Although these incidents were covered heavily in the media, they were by no means unique occurrences. According to one study, 39 students died in school-related acts of violence during the 2004–2005 school year, including 24 deaths by shootings.

These and other murders perpetrated by children against classmates and teachers have caused a furor of reactive security measures, precaution taking, and a new commitment to stringent control. Zero tolerance, which initially referred to students carrying weapons to school, fueled provisions for suspension and expulsion and increased them. In Chicago, in the wake of commitment to zero tolerance, suspensions and expulsions jumped to an average of 90 per week, mostly Latinos and African Americans. Proponents of more stringent codes pointed to the staggering fact that every day in the United States 12 children are killed by gunshot. The fact that one day they were gathered together in their deaths at Columbine brought national consciousness to a new level. Many schools nation-wide, particularly in urban settings, instigated entry-area body and bag searches, stricter dress codes, and random drug testing. Yet critics of this stringent disciplinary action urged educators to return to a positive vision of students and search for punishments that teach rather than using those that increase the drop-out rate.