police are now looking for him. home. >> mollie tibbetts' family hit the streets handing out flyers in the small town of brooklyn where she was reported missing after an evening jog. authorities are now hoping an exercise tracking device will lead them to her. here's abc's gio benitez. >> reporter: the fbi joining the intense search in a small iowa town to track down missing college student mollie tibbetts. investigating the possibility that she may have been abducted. >> for a 20-year-old to got missing and completely kind of fall off the grid, it's obviously a very suspicious and very serious matter. >> reporter: volunteers already combed the area where she was last seen running a week ago today. agents now zeroing in on her digital footprint. authorities say fitbit is providing information in the case in response to a search warrant. tibbetts' boyfriend dalton jack said she always wore her fitness tracker. he said he began to worry when he realized that she hadn't read his messages...