article_snippet: Dun Meng recalled seeing the flashing lights of police cars in Cambridge earlier that night.
article_snippet: I thought it was just a typical robbery.
article_snippet: There was nothing typical about the days after the Boston Marathon bombings, which killed three people and hurt more than 240 others.
article_snippet: Timeline of the bombings, manhunt and aftermath .
article_snippet: New surveillance footage revealed .
article_snippet: CNN Ann O'Neill reported from Boston, Ray Sanchez wrote from New York.