The feds say they didn't have anything concrete on the elder Tsarnaev and were interviewing him at the request of a foriegn government. This is after they denied even talking to him.

CBS News:

As first reported by CBS News correspondent Bob Orr, the FBI interviewed Tsarnaev, the elder brother of at-large bombing suspect Dzhokhar A. Tsarnaev, at the request of a foreign government to see if he had any extremist ties, but failed to find any linkage.

Both Tsarnaev brothers were legal permanent residents of the U.S. There is no evidence so far that either brother received any tactical training.

CBS News correspondent John Miller reports it is likely Russia asked to have the elder Tsarnaev vetted because of suspected ties to Chechen extremists.

The FBI is likely to have run a background check, running his name through all the relevant databases, including those of other agencies, checking on his communications and all of his overseas travel. Miller reports that culminated in a sit-down interview where they probably asked him a lot of questions about his life, his contacts, his surroundings. All of this was then written in a report and sent it to the requesting government.

Is this true? The mother of the terrorists has a different story:

Zubeidat Tsarnaeva said her son got involved in "religious politics" about five years ago, and never told her he was involved in "jihad."

She insisted the FBI "knew what he was doing on Skype" and that they counseled him "every step of the way."

Tsarnaeva, who is a U.S. citizen currently in Russia, told Russia Today the FBI had called her with concerns about her elder son, although she did not specify when exactly she was contacted.

"They used to come [to our] home, they used to talk to me ... they were telling me that he was really an extremist leader and that they were afraid of him," Tsarnaeva said. "They told me whatever information he is getting, he gets from these extremist sites... they were controlling him, they were controlling his every step...and now they say that this is a terrorist act!"

I doubt whether the FBI was "controlling" him. But might they have made contact with his family? Just how concerned was the FBI about Tamerlan? Did they have him under any kind of surveillance?

Given that the FBI denied ever interrogating Tamerlan, one wonders how much we can trust the feds to give us the truth about their interest in the Tsarnaevs.