An aunt of the elder Boston bombing suspect says he struggled to find himself while trying to reconnect with his Chechen identity on a trip to Russia last year.
Tamerlan Tsarnaev "seemed to be more American" than Chechen and "didn't fit into the Islamic world", his aunt Patimat Suleimanova told The Associated Press.
Ms Suleimanov added that Tsarnaev spoke daily on Skype to his American-born wife, who had recently converted to Islam, and that she instructed him on how to observe Islam correctly.
Investigators are focusing on the six months Tsarnaev spent last year in southern Russia, where he stayed with his father for at least part of the time.
Tsarnaev was killed in a gun battle with police. His younger brother, Dzhokhar Tsarnaev, was later captured alive, but badly wounded.