Brad Spicer. Protecting our schools is incredibly complex and tragically imperfect. As school leaders look to enhance access control, it is important they understand the primary purposes of a secured main entrance. In the simplest of terms, the purposes are prevention and mitigation. A secure entrance can prevent unauthorized entry by presenting a more positive security image. When prevention fails, the entrance should mitigate an intruder’s ability to enter the school. This should create a delay that provides staff time to call 9-1-1 and implement intruder response plans.