Data from the Federal Bureau of Investigation and other sources indicated that violence in schools throughout the United States increased at epidemic rates in the 1970's. In addition, programs aimed at ameliorating violence and vandalism in schools increased in popularity. Many public schools implemented programs that employed uniformed police officers, sophisticated alarm systems, tightened security measures, and other preventive activities. During the period between 1970 and 1973, there was a 77-percent increase in assaults on teachers, an 85-percent increase in assaults on students, a 37-percent increase in robberies of students and teachers, a 40-percent increase in rapes or attempted rapes, an 8-percent increase in homicides, and a 53-percent increase in weapons confiscated from students. Concern also developed in the 1970's about juvenile drug use and juvenile gangs. In the 1980's, adolescents between 12 and 15 years of age were twice as likely as older teenagers to experience crimes in the school setting. In 1988, experts estimated the yearly cost of school vandalism at $5 million. Possible solutions to school disturbances and violence focus on shared beliefs and values, respect, explicit safety and violence prevention policies, holistic staff development, learned strategies, parental involvement, student dispute resolution through innovative initiatives such as teen courts, and school safety plans.