the republican chairman of the house homeland security committee. >> if he was on the radar and they let him out of their sights, that's an issue certainly for me. >> reporter: tsarnaev's contact was made public by the man's mother who suggested agents had been harassing her son for years. >> they knew what my son was doi doing. they knew what sites on internet he was going. how could this happen? they were watching every step of him. but this is a terrorist act. >> the fbi confirmed that in 2011 it interviewed the older brother and family members. it did not say how many times. it was at the request of russian intelligence, according to a senior u.s. official. the fbi said the request was based on information that tsarnaev was a follower of radical islam, a strong believer and that he had changed drastically since 2010. in response to the request, the