After Tamerlan and Dzhokhar  Tsarnaev were identified as the alleged bombers behind the Boston Marathon explosions, people have had no end of questions. Who are the Tsarnaevs? How did the family make their way to Watertown? And what motivated  Tamerlan and Dzhokhar to make their way to Boylston Street on that fateful day  last April?

A lot of those questions have now been answered  by way of the Boston Globe's latest reporting: The Fall of the House of Tsarnaev. One of the reporters working on this piece, Patricia Wen, joined Jim and Margery today to fill in  many of the blanks surrounding  this story.