Opinion articles and FB posts, none of which back up GP's "literally the only substantial voice" claim... So you couldn't find anything, thanks for making my point for me.
Again, where is any official BlackLivesMatter material on Daniel Shaver?
Again, where is any official BlackLivesMatter material on Daniel Shaver?
The website is not the movement.
Second, both of those "opinion pieces" have references to high profile black lives matter activists (deray, shaun king, etc) speaking out about Daniel Shaver, so that's about as official as you're going to get.
Third, that "facebook post" documents an actual event organized by the family of Daniel Shaver, thanking the local blm chapter for their support.
If you have a more substantial voice that has done more than blm in bringing attention to this issue in a productive way, feel free to bring that forward.