The advice, which stemmed from Russian warnings, was ignored.
Russia had raised red flags about Tsarnaev’s radicalized Islamist views, The New York Daily News reported.
CIA officials gave the warning to several U.S. intelligence and security agencies: the FBI, Homeland Security, the State Department and the National Counterterrorism Center, an intelligence agency spokesman said Wednesday, as cited by The New York Daily News.
Tamerlan Tsarnaev, 26, was killed in a shootout with police. His brother, Dzhokhar Tsarnaev, 19, the second suspect in the April 15 Boston bombings, is in the hospital and recovering from gunshot wounds.