I would add that many of the "school shootings" counted in the edweek.org data are not what most people would understand to be school shootings. Things like Person A shoots Person B outside of a school, nobody dies, neither A or B are students, teachers, or otherwise affiliated with the school. Edweek is providing what are known as "advocacy numbers", in that they are stretching the truth as much as they possibly can.

Your kid's chances of being killed in a school shooting are about the same as being struck and killed by lightning (many more people are struck and survive).