Secretary of Homeland Security Janet Napolitano acknowledged to a Senate panel Tuesday that her department was aware of Boston bombing suspect Tamerlan Tsarnaev’s trip to Russia in 2012.

Tsarnaev, who died after a shootout with police Friday, took the trip a few months after the FBI interviewed him because of a tip from the Russian government that he was linked to radical Islamist groups.

The FBI was not aware of Tsarnaev’s six-month trip to a volatile region of Russia plagued by Islamist violence because an airline misspelled his name on a flight manifesto shared with the U.S. government.