Somehow I missed(*) that the Department of Justice did just that investigation, and that it concluded Officer Wilson eventually shot Michael Brown in self-defense. In addition, the phrase "Hands up, don't shoot!" which came to be a slogan for people (particularly of color) expressing their frustration at police violence against members of their communities was never uttered in this altercation.
Jonathan Capehart (himself a black man, and a promoter of the #blacklivesmatter movement) discusses how this error came to be promulgated by people including himself in an article from last month's Washington Post. Capehart reviews the DOJ report, which highlights the nation-wide systemic problems of police actions toward communities of color and shows that the notion "black lives matter" is still widely supported by other well-documented incidents.
However, as regards the shooting in Ferguson, he believes that the DOJ did the full investigation that should have happened before any case was brought to a grand jury, including ballistics and DNA experts, real witness interviews and cross-checks. The results show that Brown did not utter the "hands up" phrase, and was moving toward Wilson at the time of the fatal shooting.
Like Capehart I feel compelled to reiterate that these results do not change my opinion that police violence is a significant problem, that police militarization should not be happening, and that the separation of police from the communities they are supposed to protect has led to a callous and often racist system in which colored people get abused and killed far too often.
But also like Capehart I feel we should hew to all the truths we can discover. It's true that black lives matter, but it's also true that the Brown shooting is a bad example on which to rest an important movement for social justice.
(*) My calendar reminds me that on March 15th I was a bit busy with the aftermath of Mom's death. I suspect that rather a lot escaped my notice around that time.