One of the brothers behind the deadly Boston Marathon bombing passed a test to become a U.S. citizen three months before the 2013 attack, the Boston Globe reported.
To pass the test, Tamerlan Tsarnaev, an ethnic Chechen who immigrated to the United States from Russia a decade before the attack, had to deny terrorism links and correctly answer questions about American history, as well as demonstrate proficiency in English.
But despite fulfilling those requirements, the U.S. immigration officer who reviewed his test did not immediately approve Tsarnaev's citizenship application, the newspaper reported on February 29.
Its report was based on 651 pages of heavily redacted documents released by the U.S. Department of Homeland Security.
Tsarnaev, 26, was the older of the two brothers who carried out the April 15, 2013, attack, which killed three people and injured 264. He died following a gunfight with police.
Dzhokhar Tsarnaev, now 22, was found guilty of carrying out the attack and sentenced to death last year. He is already a naturalized U.S. citizen.