Russians uncovered something even a little worse.
It turns out the family was influenced by someone they suspect had been a federal undercover operative whose job was to radicalize and then entrap people on terorrism charges.
He supposedly worked to radicalize the Tsarnaev family and then at some point "gave up".
http://news.yahoo.com/boston-bombings-misha-red-herring-070000283.html So this "Mischa" might be the Islamic version of a David Gletty...