“Federal investigators interviewed more than 200 people and analyzed cellphone audio and video, the law enforcement officials said. Officer Wilson’s gun, clothing and other evidence were analyzed at the F.B.I.’s laboratory in Quantico, Va. Though the local authorities and Mr. Brown’s family conducted autopsies, Mr. Holder ordered a separate autopsy, which was conducted by pathologists from the Armed Forces Medical Examiner’s office at Dover Air Force Base in Delaware, the officials said.
The federal investigation did not uncover any facts that differed significantly from the evidence made public by the authorities in Missouri late last year, the law enforcement officials said. To bring federal civil rights charges, the Justice Department would have needed to prove that Officer Wilson had intended to violate Mr. Brown’s rights when he had opened fire and that he had done so willfully — meaning he knew that it was wrong to fire, but did so anyway.” New York Times