BOSTON (CBSNewYork) -- The FBI investigated Boston Marathon bombing suspect Tamerlan Tsarnaev in 2011, after discovering that he was looking to leave the country and join "underground groups."
Tamerlan Tsarnaev, 26, was killed in a shootout with police on Thursday night. His younger brother, Dzhokhar Tsarnaev, 19, was captured Friday night and stands accused in the bombings that left three people dead and an estimated 176 injured.
Upon learning the suspects' identities Friday, the FBI reviewed its records and found that in 2011, a foreign government asked the FBI for information about Tamerlan Tsarnaev, saying he was a follower of radical Islam and that he had changed drastically since 2010.
At the time, he was preparing to leave the United States and travel to the unspecified country's region to join "unspecified underground groups," the FBI said.
The FBI checked government databases to investigate Tamerlan Tsarnaev's telephone communications, Web use, association with other people of interest, travel plans, and education history.
The FBI also interviewed Tsarnaev himself and his family members.
No terrorist activity was found in association with Tsarnaev, the FBI said.
The FBI did not indicate whether Tsarnaev went ahead with his plans to travel to the foreign country.
Tamerlan Tsarnaev dropped out of community college, but became a leader in the boxing ring and aspired to be a U.S. Olympic boxer. But between 2009 and 2011, those around him began to notice that he was becoming detached.
He was arrested in 2009 for assaulting his girlfriend, and in 2010, he described himself as, "very religious; I don't have a single friend because I don't understand them." He also had jihadi videos posted to his YouTube account.
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