It really smells.
Perhaps the crowd was the target and the cop wounds were accidental--poor marksmanship. But maybe the cops were the target. Black radicals might want to kill white cops, but so would white radicals want to do so to gen up conservative outrage against uppity blacks with the audacity to demonstrate, (and an uppity black Attorney General issuing damning reports), against Ferguson's Finest.
The question is, were those cops hit by murderers (black or white), friendly fire, or a deliberate political act designed to provoke whites into initiating a race war. I think all three possibilities are equally likely.