I went through the public school system and I remember having lockdown drills from 1997 onward. Teachers just locked the doors and continued teaching until the

I went through the public school system and I remember having lockdown drills from 1997 onward. Teachers just locked the doors and continued teaching until the all clear was announced and they unlocked the door. In 2014 I was working IT for a private high school which had an active shooter drill on a yearly basis. I was told they started it two years prior because a student came onto campus with a handgun. Both in southern California.