Though he isn't considered a suspect, a former Chechen separatist who is now a refugee in the United States has become a key target of information in the Boston Marathon bombing investigation. Musa Khadzhimuratov—who knew Tamerlan Tsarnaev and his wife and hosted them at his home a few weeks before the bombing—has been questioned "dozens" of times by the F.B.I., according to The New York Times,  and the feds have apparently searched his apartment, his computers, given him a lie detector test, and taken DNA evidence.

Khadzhimuratov is reportedly the current focus of an effort to establish if Tsarnaev had any contact with members of the radical Islamist community, either in Chechnya or the U.S. Although there doesn't appear to be any evidence to contradict the current theory that Tamerlan and his brother were "self-radicalized," Khadzhimuratov says he and his family have been subjected to heavy scrutiny—and he's worried that the Russians are to blame.

Other Chechens who now live in the United States remain fearful of Russia's security forces, who continue to do battle with both with independence movements and radical terrorists back in the Caucasus regions. A reporter for the Voice of America tells the Times that those immigrants and refugees are worried that the FSB might attempt to frame them for the Boston bombings, perhaps as revenge for earlier run-ins back in their homeland, or as a way to justify continued military operations against rebels back in their own country. The theory is that tying Boston to the separatist movements in Chechnya and Dagestan would the give the Russians cover with (and even possibly cooperation from) the U.S. in fighting their own homegrown wars.

Much like the Tsarnaev's parents, who have insisted more than once that their sons are innocent, the belief that the Russian government (or any government) would go to such lengths to discredit or punish its enemies is not uncommon. Or entirely unjustified.

Khadzhimuratov came to the U.S. in 2004, but back in Chechnya he was a bodyguard for Akhmed Zakayev, a man described as a "prominent secular Chechen separatist leader" who is now in exlie in England. In 2001, Khadzhimuratov lost the use of legs after being shot by Russian forces. He later brought his family to the U.S. and his wife and two children have since become citizens, but he has apparently been denied a green card because of his connection to the war. A Twitter account that appears to belong to him was created two years ago, but only contains a brief series of messages directed at Senator John McCain, pleading for his assistance.