Martin Bashir 04/19/13

Unclear whether Boston bombers have any direct links to Chechen groups

Former White House counterterrorism official Roger Cressey and, later, NBC’s Richard Engel join Martin Bashir to discuss how strong – or weak – the ties could be between Tamerlan and Dzhokar Tsarnaev, the two brothers accused of the Boston Marathon ... more Duration: {{video.duration.momentjs}}