Because this is statistically the form of policing most likely to get cops shot.
> Why does every cop in a school need a gun?
A symptom of America's school shooting problem. When your child is being gunned down you'll probably wish the police there were armed.
2018 was much worse with 37 kids killed in school shootings.
This is roughly the same as the number of unarmed black people shot and killed by police in the line of duty (at least this number has been trending downward for several years).
Reporting of school shootings is notoriously unreliable:
https://www.npr.org/sections/ed/2018/08/27/640323347/the-sch...
The 2018 numbers I was referencing was from this 10 year overview [3].
[1] - https://www.edweek.org/ew/section/multimedia/school-shooting...
[2] - https://www.edweek.org/ew/section/multimedia/school-shooting...
[3] - https://www.cnn.com/interactive/2019/07/us/ten-years-of-scho...
Because civilians have shot and killed police during traffic stops? And not just with guns. I seem to remember a road rage case in Colorado where the raging driver shot and killed another driver with a crossbow.