The narrative changes to fit the politics of the racialist pimps. In Ferguson it was a white racist cop and an innocent teen-ager; but then a Department of Justice investigation found nothing criminal and there was no, "hands up don't shoot." Michael Brown had just robbed a minority owned store, and he reached in the policeman's car when being questioned.
Then in Baltimore six police, three of them black, were arrested in the death of Freddie Gray, a black man who died being transported after a struggle; again no evidence to convict and it was clearly a reflexive racial action by Marilyn Mosby, the black female city State's Attorney. The police involved were black, white and one female with a total of about 50 years employment by the city which takes millions every year from the state and federal governments to just stay open and fix poverty. Narrative began to shift--it's not just racism, it's police wanting to kill black people.
Killing the Dallas police is a different story, it was a peaceful protest, and at least some in the Black Lives Matter movement claimed it was justified and in retaliation, but to my knowledge no one has been arrested as the narrative is that police lives don't matter even if protecting blacks from criminal elements.
Then Tulsa and Charlotte. The policeman in Charlotte was black and the one in Tulsa was a woman; so the racist angle was totally destroyed even though Hillary Clinton ran with it, after she urged patience in the NYC bombing until more investigation was finished. Shouting racism is OK; suspecting terrorism is not. 70% of the people arrested during the Charlotte riots are said to have ID from out of state (I haven't checked that figure--just saw a news item). We know the Charlotte conflagration is not grass roots, but who ginned up the hate is not known. It looks suspiciously like a Soros sorry soiree. But now the narrative is changing to it's "pent up rage going back to slavery days and Jim Crow"--and for that WalMart must be looted and Air Jordans stolen. For that another black man who was rioting was killed by another black. Who will put those black families on TV, or doesn't their grief matter?
Meanwhile in the same two year time frame from Michael Brown in August 2014 to Keith Scott in September 2016, statistically we know that twice as many whites were shot by police, most for good cause because they were committing a crime like holding up a small store and fleeing or resisting arrest or grabbing a policeman's gun or something else stupid. And we know from Heather MacDonald's excellent crunching of numbers for her book War on Cops that a police officer has 18.5X the risk of being killed by a black man as an unarmed black has of being killed by police.
Again, the actual facts do not benefit any black congressman, or president, or attorney general, or Black Lives Matter leader, so the facts will be ignored and more hate will be dumped on police, and more white college students must take mandatory classes on why they are bad people because of their race.
This is Obama's legacy.