There are three key strategies that law enforcement agencies should follow when developing plans to secure a school. One strategy is to develop a strong partnership with the school staff, volunteer organizations, and students. Informing these groups about law enforcement's role on the campus and enlisting their support and involvement is critical to success. A second strategy is to take a practical approach. It is impossible to eliminate risk completely; however, law enforcement officials should aim to minimize risk. This may involve making campus policy changes or investments in access control technologies that prevent unauthorized intruders from entering buildings, or students from bringing weapons to schools. A third strategy is to build preparedness through regular, ongoing training and communication. Law enforcement should work with school administrators in practicing response exercises, so that all members of the campus know what to do and how to protect themselves and others in an emergency. Regarding tactics, police agencies should conduct an area assessment in order to determine the characteristics of the community and environment surrounding the school. This will identify risk levels. Because the greatest security threats often come from inside the school building, however, risk assessments on campus must also be assessed. On-campus security assessments may be conducted by the school resource officer (SRO) and should include vehicle and pedestrian safety on school grounds, perimeter fencing, evaluation of playgrounds for vulnerability, evaluation of sports fields for vulnerability, and crime prevention through environmental design. Security technologies should also be assessed. These include surveillance video that can be shared over computer networks, access-control technologies that provide instant information on the likely location of intruders, and software systems that facilitate security monitoring.