Hi clo,
These things may be accidental. One has to be careful of the media bandwagon. The video we have is where there appears to be a major issue. The surrounding stuff, maybe so, maybe not. MSNBC and CNN will declare racism and police cover-ups sight-unseen. "Outrage!" sells air time and hence, advertisements.
For the moment, in real life, it's a bad cop story with perhaps the whiff of omerta.
On the other hand, the cop was charged with murder, albeit after a lengthy investigation. So at least there is some sense of responsibility in play.
They have to be sure not only that he killed the deceased but that he clearly violated departmental policy in dealing with a person carrying a weapon.
If you want to change policing, it isn't putting an officer on trial that will change it. It is amending the department's standard operating procedures one at a time. And more generally also finding better ways to protect the police from armed people (not relevant in this case but the wide distribution of guns makes harsh operating procedures inevitable), finding better non-harmful ways to disarm people, finding solutions to mental health problems and doing a better job of fixing issues with drug use.
The US has more and maybe bigger problems than Moslem extremism.