Here are two basic examples.
First is Michael Brown. Who was a black male who violently attacked a convenience store clerk and then attacked a police officer moments later. The officer who was attacked was Darren Wilson, who was a white male. Would anyone here deny that race was not the core of the discussion in the popular media and by black people in general? At the very least you would not be crucified and would probably receive support if you pointed out the officer was white and probably racist for having to kill a black "unarmed"(as if that makes a 6'4 250 lb 18 year old with a proven history of not being afraid to use violence completely harmless) male.
So that was one example where it is completely OK to point out race. The common thread seems to be that its a black victim and a white aggressor. But statistically this is the least likely of violent crimes by almost a 5:1 margin. That is, blacks are 5x more likely to commit a violent crime against a white person than the reverse.
Two videos here which no one knows the name of anyone involved and honestly attracted almost no attention yet is, STATISTICALLY, the much more common violent crime, yet race is never mentioned. Despite there being actual documented proof and not just hearsay, unlike the Michael Brown or Trayvon cases, people immediately give the teens shown the benefit of the doubt. If you tried to say black people have an issue with violence and this video demonstrates that you will be called a racist, disregarded or worse.
Here are some actual examples of how race was scrubbed from the article by popular news and even reddit. On reddit they mentioned race and it was flagged as a misleading title. On huffington post they just completely ignore race.
Why in one scenario is it OK to point out race and in the other completely unacceptable? Is it because white people are scared of pointing out that blacks may have a problem with violence? Is it because black people are so loud in the media and their voice has just drowned out all others at this point that you actually believe that blacks are this persecuted minority that seems to be just dying for no reason at the hands of whites, cops or otherwise?
I would love a legitimate response to this question but don't actually expect one.