Your probably right that it is more complicated but using the racial angle to play up black distrust of authority and fears of injustice are what ignited the present shit storm. Sharpton wouldn't be involved otherwise.
This isn't the least bit complicated.
-Zimmerpig wanted to be a cop, couldn't be a cop, wanted to kill someone, anyone.
-Zimmerpig killed the kid.
-Dumbass cop bought his "self defense" story.
-Dead kids family weren't very smart.
-cops thought they could hide their bungling incompetence.
-People found out.
-Zimmerpig is a murderer.