The police in suburbs and small towns are extremely nice and helpful to old, white people. I don’t know of that refutes your case or supports it.
BUT, I had several policemen from big, rough, immigrant cities as patients. These guys were anxious because of the dangers in their jobs, and because some of their colleagues made things more difficult and dangerous for them. I would say that about 40% of police want to make the world and their community safer and more livable. Another 40% have been doing it for 15 years and want to do what they need to do to get their pension. Maybe 20%, if that, are the ones you describe, but often those are the ones who set the tone for the culture.
It’s part of what is struggling to change in our world these days. It is still a struggle, but it will change, especially as it is being called out more.