If the man was white would he have crouched on his neck? Not sure. Its not fair really. I don't even think the man that was killed did anything wrong, I think the cheque was given to him and it wasn't fraudulent.
If you are reading this now and have experienced racism then I can only say I pity you because you were judged by your body and not your mind or character, that isn't fair. Keep your chin up if you can and remember that life is short and try to be optimistic. Look for excellence in yourself and rise above the prejudice. I can say no more.