Far too many appear to be thugs, racist or otherwise.
I recently watched a police programme - it showed a US cop stop a car and he told the woman driver to get out of the car. Because she didn't move as fast as he wanted, he tazered her. She fell out of the car onto the ground and every time she tried to stand up he tazered her again because she wasn't getting up fast enough. He tazered her five times. I can't even begin to imagine how horrendous that would be. They said he subsequently retired early from the police. WTF he should be in prison for assault. Not to mention how trigger happy they are - it seems to be shoot first, ask questions later.
The police are honestly one of the main reasons I would never go to America.