This longish (well, longer than a blog post) article by Jamelle Bouie, about the long history of official racism in Ferguson, does the most to supply context for the protests (and even the looting) in Ferguson of any article I’ve seen.
Somewhat related: Nobody Knows How Many Americans The Police Kill Each Year | FiveThirtyEight. The fact that we don’t even have an effective system to track deaths caused by police is appalling.
Both links via Obsidian Wings.
Deadspin, of all places, is attempting to compile a list of police shootings from 2011-2013. They’re asking people to take a day and do an in-depth search for news articles; there’s more info at the link.