One of the issues that comes to the forefront when dealing with a school shooting is the psychological impact it can have. The Psychological First Aid intervention provides guidance on responding to disaster, violence, or terrorism events. This version gives school administrators, educators, and staff practical assistance to meet immediate needs and concerns, reduce distress, and foster adaptive coping in the wake of a disaster. The manual includes in-depth information about each of the eight core actions and accompanying handouts for administrators, school staff, educators, students, and parents and caregivers. Here is a link from the National Child Traumatic Stress Network and the National Center for PTSD for the:
Psychological First Aid for Schools Field Operations Guide
https://www.nctsn.org/resources/psychological-first-aid-schools-pfa-s-field-operations-guide