Police and federal agents appealed to the public Tuesday for amateur video and photos that might yield clues to the Boston Marathon bombing as the chief FBI agent in Boston vowed "we will go to the ends of the Earth" to find whoever carried out the deadly attack.
(UPDATED 8:45 p.m. with more local runner information, video) Two bombs exploded near the finish of the Boston Marathon on Monday afternoon, killing at least two people and injuring more than 100 others.