police never found anybody with a gun. what they did find was a man running away from them, down this bridge. they chased him, shot him and killed him. two people were killed that day. ronald madison was one of them. another four were wounded. the seven police officers involved have always said the shooting was justified. the new orleans police department, which investigated itself, agreed. the more critical question is not the seven guys on the bridge, but can this police department investigate itself. reporter: police say they fired in self-defense when madison reached for his waist and turned on them. but cnn has been uncovering details that raise doubts. an autopsy revealing madison was shot in the back. lack of any evidence madison was ever armed. and finding a witness who says he saw officers line up and gun down a man running away. with all motion moving and