Not sure how you look at charts like this and not see that is is a rather unique issue to one country
https://static.prisonpolicy.org/images/policekillings_rates....
https://static.prisonpolicy.org/images/policekillings_rates....
Maybe try a source that calculates every country? https://worldpopulationreview.com/country-rankings/police-ki...
I agree the US has a violence problem on par with third world and war torn nations. However, the US is neither of these. Why does the violence persist?