This bill provides immunity from civil liability for a teacher, and the school districts or charter schools that the teacher works for, if the teacher intervenes in an incident involving violence in order to safeguard himself or herself or a student. The bill requires the teacher to follow procedures and to intervene in good faith in a manner that the teacher reasonably believes is afforded the defense of justification under Chapter 563, RSMo. The bill prevents school districts from the implementation of a policy that prevents teachers from protecting themselves or students.