On April 15th 2013, two bombs explode during the iconic Boston Marathon, killing three spectators and injuring hundreds others. In a race against time, investigators, using state of the art technology, circulate images to the public.On April 15th 2013, two bombs explode during the iconic Boston Marathon, killing three spectators and injuring hundreds others. In a race against time, investigators, using state of the art technology, circulate images to the public.