Police Brutality, why do they get away with it?

Surely some of you seen the video of police kicking a mental man while he was down, broke his ribs, punctured his lung, etc. The police always get away with it, even though it was on film.
I am a victim of police brutality, how can I possibly win if they get away with murder?
There is no "Innocent until proven guilty!" The police think they’re the judge and jury. This is just wrong! Has anyone else here in the US been a victim of this crime too?
The police will lie for the "bad" ones, they all stick together even though it’s a lie, so even the so-called "good" ones are then "bad" as well.
Everyone is supposed to be "Innocent until proven guilty." Some of the answers I’ve seen on here prove that everyone is guilty just for being arrested!
Most have proved my theory of this correct.
This has nothing to do with not seeing hands, resisting arrest, running from the police, or police feeling their lives or someone else’s life is in danger. It’s just about bad cops abusing their power to be judge and jury.

yeh watch the news its all over they shot a man 50 times that was getting married the next day then they shot another man like 3 days later why do they get away from it hmm thats a good question i think its cuz they know they can i mean if they get in trouble how would that make the commisiner look or the president that is why they protect them to make them look good and us the people look like were the ones guilty and their cops look like angels also remember they are the biggest gang in the world something to think about =)