You forgot that they were trained to expect the unexpectable. They are not like you and me with no prior training against violence. They were trained to expect violence and what to do when that happens. Compared to other violent crimes, school shooting is probably mild relatively speaking. Don’t officers deal with active shooters outside of school? I don’t see how school shooting is any scarier than dealing with seasoned criminals and freezes four deputies to non-action. I would call for a full review of the sheriff department. They also got 18 calls regarding Cruz including a few about his gun collection that went unheeded.