This presentation from Michael G. Planty of the Bureau of Justice Statistics provides an overview of school crime and safety. Some highlights from the presentation include: " During the 2010-11 school year, 11 homicides of school-age youth occurred at school.  In 2011, students age In 2011, students ages 12 to 18 experienced about 1.2 million nonfatal victimizations at school, including 649,000 thefts and 598,000 violent victimizations. Total violence and theft are down since 1992.  In 2011, about 28% of 12- to 18-year-old students reported being bullied at school during the school year.  Between the 2000 and 2010 school years, public schools increased the use of safety and security measures."
U.S. Census Bureau: http://www.census.gov/