It's also within the context of years of peaceful protests in this community leading to no real change. Jamar Clark and the "occupation" of the 4th Precinct, Philando Castille, the various and repeated freeway shutdowns by BLM activists that resulted in charges of 'rioting' that had to be fought in court (and which utterly outraged many whites in the area for daring to restrict their freedom of movement). This has been building for awhile.
I also spoke to a good friend who has been involved in those protest actions above, has been arrested in protest, petitioned the city council, sat in meetings, organized, etc. His basic message today was "we're burned out -- there's no leadership organizing this thing."