I attended Greenfield schools from 1st grade trough graduation. After 10 years away I returned as a member of the teaching staff in 1970, retiring in 1996. Except for 1 year teaching at a California high school, Greenfield is all I ever knew.
Greenfield schools, by design, are very open. There are many buildings and lots of exterior doors. In my 38 years of being on that campus as either a student or a teacher I can only recall two instances of a potential violent threat. I remember a student in the elementary grades building a bomb and placing it under a teacher’s desk. I don’t remember if the bomb was real or how knowledge of it was learned.
The second occasion took place immediately outside my classroom door when a student shot himself in the torso. At no time were other students in danger. The firearm was immediately sequestered and the student attended to.