The Kelly Thomas case in Fullerton, California, sure seems like a clear case of police abuse. Not all the facts are known publicly yet, but what is known paints a picture of some sadistic behavior by somebody.
I hope the independent investigations (more than one?) find out what the real story is, and if somebody needs to be held accountable for justice to be done, then so be it.
See the history of this unfortunate case at Wikipedia:
Kelly Thomas (beating victim) - Wikipedia, the free encyclopedia