Among the things investigators are examining: A six-month trip to Russia, an outburst at a Boston mosque, and Tsarnaev’s YouTube page linking to a known Russian militant. The video portrayed a massive gun battle eerily similar to the one that unfolded in Boston on Friday.
There’s also growing criticism of the FBI by some lawmakers, who ask how much the agency really knew about Tsarnaev.
“The FBI was told by Russian intelligence several years ago that the older brother had possible terrorist connections in Chechnya and Russia. He was investigated by the FBI and they basically gave him a clean bill of health,” said U.S. Rep. Peter King.
While it is still unclear whether the Tsarnaev brothers acted on their own or if they had training from outside groups, King said he wants to know more.
His concerns were summed up in a letter from King and Congressman Michael McCaul of Texas addressed to the head of the FBI, Robert Mueller, and Secretary of Homeland Security Janet Napolitano. They demand to know all information the government had on Tsarnaev prior to the April 15 Boston Marathon attack.
“Why didn’t they keep the file open and go back and check it out when they found out he went to Russia,” asked King.
“What I can tell you is that the FBI, as the FBI itself has said [it] thoroughly investigated the information that it received in 2011. That included checking U.S. government data bases and other information to look for such things as derogatory telephone communications; possible use of online sites associated with the promotion of radical activity; associations with other persons of interest, travel history and plans and education history,”said White House Press Secretary Jay Carney.
The FBI maintains interviews were conducted, but no threat was ever established. As for letters from lawmakers, the agency said they will be addressed through the appropriate channels