Police Brutality

I am currently much more aware of police conduct as I am doing a unit on the Police for uni, but it seems like police are in trouble a lot at the moment.
In Victoria we have the Office of Police Integrity (OPI) which has been holding enquiries into the Armed Offenders Squad. This squad had the highest number of complaints from the public, which is why they are being looked at first. Last week a senior officer "collapsed" on the stand after being shown a video which contradicted his earlier denials of assault. The Police union has been screaming that they are being scape-goated and that it's a witch hunt and so on. My response to this is pretty straight forward - a witch hunt is based around falsehood, clearly this investigation is not, or the senior police officer would not have reacted the way he did on the stand.
Now today in the news there has been an incident in Queensland where a police officer beat and kicked a Palm Island man, Mulrunji Doomadgee, to death in 2004. Was he prosecuted? No. Was he fired? No. Was he given a week's holiday, and then back at a deskjob? Yes, apparently that is all the punishment a police officer deserves after killing a man. Peter Beattie, the Queensland premier thinks that's ok. Well I suppose he was "only" an Islander. A local elder called it "institutionalised racism". That type of mentality makes me sick.
What is totally shocking is that after probably two decades of inquiries and public out cry over deaths in custody and the treatment of people by police, especially of Aboriginal people, you would think that the cops involved might stop for a minute and think "oh maybe I SHOULDN'T kick this person to death..." or "Maybe beating a false confession out of this man might get me in trouble...".
Clearly I have made an error - I have assumed that these people actually think.