>> you know, the wars in iraq and afghanistan have been going on for a decade. when you see somebody who's self radicalized, there's usually another turning point. somebody who influences them. now we're learning from tamerlan's uncle, who says there was a such person, a person here in cambridge, 2009. and the uncle said that this person was really getting into tamerlan's head and telling them all about radical islam. he was worried about he actually called a family friend to see what it's about. here's what the uncle told us. >> i called one of the gentlemen living in that area. i said listen, do you know what is going on with that family? with my brother's family?