physically did it start? where did it -- what's the path it was on? they're look at all sorts of records here in the united states, having been a former prosecutor, they're going to look for credit card receipts, for gasoline, look for tolls, look for gps, sorts of things, you know, we use all the time. you know, used to be paper maps, now we have gps, we have cell phone, we have blackberries. all these things hit towers. will tell you your location at specific times. they will try to get all this information, john, in order to paint the picture, if you will, chronology of where this car was in minutes, hours and days before it ended up at 45th and broadway. >> the new york city police commissioner ray kelly says they're looking based on the video, first person of interest is a 40-something white man, in his 40s, seen leaving the scene, changing clothes and looking over his shoulders at if worried about something. that's from the police commissioner. secretary of homeland security janet napolitano says it's an apparent one-off.