You wonder about the stupidity of government officials in Missouri. I mean, let's decide to have a secret proceeding. Then let's declare a state of emergency weeks before anything happens. Then let's call out the National Guard. What were these people thinking? How dumb could they be?
Well, I'm not sure they were that dumb. What if they were trying to obscure the issues that are just as important as the shooting? For instance, the bad behavior generally of the police in Ferguson--their bad habit of stopping African Americans for any reason, or no reason at all, their excessive fines and fees that provide most of the budget for the Police Department there, and so on.
More important, these kinds of behaviors aren't limited to Ferguson, or to Missouri, for that matter. California is a leader in increasing fees for minor infractions to fund the government. Fees can be increased easily, while increasing taxes requires supermajorities. And because police patrol low-income neighborhoods much more intensively, they're much more likely to catch people making California stops, crossing against the light and the like.
In the private sector we have payday lenders, in the public sector the petty justice system, both inclined to part poor people from their meager incomes.
Update: The Onion gets it in a paragraph.