Russia alerted the FBI several times about potentially dangerous Tamerlan Tsarnaev, one of the two Boston bombing suspect.

      The FBI, however, failed to find any links the ethnic Chechen might have to Al Qaeda, so they closed the case.

      During a security briefing for senators, US Secretary of Homeland Security Janet Napolitano told they were aware of Tamerlan’s trip to Russia’s Dagestan in 2012 while the FBI overlooked that due to a misspelled name.

      Senators raised hard questions over the flow of information between the agencies.