Obama didn’t need any evidence or actual information. He knew that the Cambridge police were racists.
Obama doesn’t need courts or jury decisions, he knows that police are racists even when found innocent by the courts.
Obama was calling the police racist, hours before they got executed by a black racist.
Then he went to the funeral of the officers who were killed for being white, talked about himself, and lectured white people for being racist.
Obama says not to despair.