Also consider the possibility that there's propaganda benefit to making the public think it's common.
From your comments, it seems that because you can show that it's relatively rare, nobody should expect, plan for, or train for it. I look at stats that show police murder rate comparable to the general population and I am honestly impressed that they are able to keep it that low while dealing with some of the most dangerous elements of society. Do you believe it is because violent criminals have a similar level of hatred towards police as they do a member of the general public, or is it because police train for the worst case scenario?
Training is another key aspect of the problem.
https://www.motherjones.com/politics/2017/02/dave-grossman-t...
In 2019 there were 48 cops killed in the line of duty by 'felonious acts'.
6 were killed during traffic stops
https://www.fbi.gov/news/pressrel/press-releases/fbi-release...