answer question also raise many question case van stop four time police van driver give testimony yet perhaps shed light happen freddie gray investigation death baltimore resident freddie gray find evidence fatal injuries cause videotape arrest interaction police officer accord multiple law enforcement sources.the source speak abc7 news brief find police report turn prosecutors thursday source say medical examiner find gray catastrophic injury cause slam back police transport van apparently break neck head injury sustain match bolt back van.details surround exactly cause gray slam back van unclear officer drive van yet give statement authorities also unclear whether gray head injury voluntary result action.the medical examiner office decline comment open investigation say release preliminary find via wjla break freddie gray head injury match bolt door transport van