Police departments in the US were not founded to fight crime, they were founded to deter and to reverse the escape of slaves.
The cycle of violence against the black communities continues, unbroken. It’s obvious that doing the same thing over and over is never going to produce a different result. This must be the result that some in power still want. Slavery may be over, but it’s not really. Ask the Amazon workers in Bessemer.
A racist institution will continue to be racist. When action is taken to make it less racist, the wounds inflicted on the institution will heal. And it will be racist again/still. Maybe even stronger at the broken places. Yes, that principle works for evil as well as good.