In America, he had been a cocky and charismatic heavyweight boxer who wore fancy pointy leather shoes and slick white shirts down to the gym. In Dagestan, the volatile southern Russian region where he lived for a time as a teen and returned to spend the first half of 2012, he became a quiet young man who spent his days online studying Islam, nursing a growing anger against heretics. Exactly what turned Tamerlan Tsarnaev into the suspect accused of three murders and mass wounding in the Boston Marathon bombings may never be known. He died in a gunfight with police leaving no explanation. His younger brother and alleged co-conspirator Dzhokhar is in hospital, barely able to speak. But a picture has emerged in the days since Tamerlan was killed of a proud but angry young man who never quite achieved his own idea of the American dream, but found solace instead in a radical form of Islam adopted by fighters in his homeland. What now seems clear is that he was deeply influenced by a few mo