Authorities released surveillance video showing the fatal police shooting of Boston beheading plot suspect Usaama Rahim in a press conference Monday. The blurry video appears to show Rahim walking to a bus stop, where he is approached by law enforcement. The officers then appear to back away from Rahim as he moves towards them. "They're not doing that unless there's a real live threat being posed," Boston Police Commissioner William Evans said, referring to the officers' retreat. The video then shows the officers shooting Rahim. It is not clear enough to make out what Rahim has in his hands, though law enforcement said it was a knife.