All of that is seen through the filter of the media. They have a story that they want to sell. They need to grab eyeballs. They are also political, and so they want to push what helps advance their own political goals, even if it tears the country apart.

Specifically, every one of these is subject to selection bias:

  "nearly always white"
  "unnecessarily violent tactics"
  "nearly always Black"

You won't see a news report when the tactics are peaceful, when a black cop is involved, or when the supposed victim is non-black. Nobody is going to riot over that, so why report it? It goes unseen by you, so you get the wrong impression about reality.

A different sort of bias comes into play with word choice, using "victims" to refer to people who typically are violent criminals being apprehended. The word ought to be "perpetrators", "suspects", or simply "criminals".