Missouri police officer who killed Michael Brown faces no charges - CNN

"Could we prove beyond a reasonable doubt that when Darren Wilson shot Michael Brown, he committed murder or manslaughter under Missouri law?"

"After an independent and in-depth review of the evidence, we cannot prove that he did," Bell said.

Wilson shot Brown, who was not armed, after a struggle ensued when Wilson stopped Brown on a Ferguson street.

"I also want to be clear that our investigation does not exonerate Darren Wilson," Bell said, pointing out the difference between proving a case during trial and "clearing him of any and all wrongdoing."

"There are so many points in which Darren Wilson could have handled the situation differently, and if he had, Michael Brown might still be alive," Bell said.

"But that is not the question before us.