School shootings continue to occur with some frequency and impact families and whole communities. The California School Resource Officers’ Association has been conducting a series of trainings related to proactive and reactive steps to avert school shootings or to mitigate the damage. One of those trainings is Safeguarding Schools: Emergency Readiness in the 21st Century. This article summarizes part of that training by providing 12 Critical Steps for schools and is separated by 8 proactive and 4 reactive steps. While some of the strategies overlap between proactive and reactive the message should be that schools must implement both types of strategies simultaneously.