Something struck Tamerlan Tsarnaev 's aunt when her nephew arrived in southern Russia last year . He prayed regularly , she said . He avoided looking women in the eye . His transformation into a devout Muslim was a radical change . Less than a year since Pateimat Suleimanova last saw her nephew , he is dead . The FBI says he and his younger brother were behind the Boston Marathon bombings that killed three people and injured more than 170 . Authorities say Tsarnaev died after a gunfight with police early Friday . But the suspects ' possible motive remains a mystery . And a key question has emerged as investigators comb through clues : What did Tsarnaev do during a trip to Russia from January to July of last year ? According to family accounts , Tsarnaev visited Makhachkala , where his father lives . After Tsarnaev returned to the United States in mid-July , a video of an Islamic militant known as Abu Dujana was posted and then removed from Tsarnaev 's YouTube channel . Suspect posted video of jihadist , analysis shows . Five months after Tsarnaev left Makhachkala , Russian security forces there killed Abu Dujana during a gunbattle that left a home in shambles . It 's unclear whether Tsarnaev ever met Abu Dujana , or had any ties with the militant group he led . Information about Tsarnaev 's trip to Russia has been hard to come by . But speaking to CNN from Makhachkala on Monday , Suleimanova revealed new details about what Tsarnaev did there , and how his family perceived his behavior . The Dagestan connection . Side trip to Chechnya . Suleimanova said Tsarnaev traveled to Chechnya twice , likely going to see his father 's family in Gudermes and Chiriyurt -- towns less than 200 kilometers ( about 125 miles ) away that were flashpoints in fighting between Russian forces and Chechan rebels during their longstanding tensions in 1990s . Tsarnaev was born in 1986 in Kyrgyzstan to an ethnically Chechen family , his uncle said last week . His birthplace is in a part of the world that 's no stranger to violence or terrorism , and the Tsarnaev family saw that firsthand . The family fled violence in Kyrgyzstan and lived in Chechnya when war broke out there between separatists and Russian forces in 1999 , Suleimanova told CNN . But she described her nephew 's visit to the region last year as a peaceful trip focused on rebuilding family connections . `` He tried to reestablish family ties . ... He went to see people , people came to see him , and of course , he went to pray , '' she said . During the trip , she said , what surprised her and others in the family was the way Tsarnaev 's behavior had changed since he went to the United States in 2003 . It had become more conservative . `` They had n't prayed before they went to America . Nobody taught him , '' Suleimanova said . `` He learned everything himself . '' The change was notable , she said . `` At the same time , '' she said , `` we were happy about it , because he did n't start doing drugs or alcohol and adopted the path to Islam . '' Tsarnaev 's parents were n't as devout , she said . `` And it is very strange to me that it was him who adopted Islam , not his father , not his mother , but himself , '' she said . `` But it 's not so strange because nowadays the children study Islam and teach their parents , and that 's exactly how it turned out with him . '' Tsarnaev 's behavior made his beliefs clear , she said . Source : Suspect says brother was brains behind attack . `` You know , he and other men do n't even touch other women , I mean , he does n't speak to them ( other women ) , '' she recalls . `` He could speak to his sisters , his cousins and me , and other women are of no significance to him because it 's a sin to even look at other women in the eye . '' That faith , Suleimanova said , was one reason she believes there is no way her nephews could be behind the Boston bombings . `` In Islam , killing a non-Muslim is like killing all humanity , '' she said , `` and killing a Muslim is like killing the whole world . '' Suleimanova recalled being with Tsarnaev 's parents last week as the same grainy pictures of their sons that were broadcast around the world flashed on their television screen . His father , Anzor Tsarnaev , pointed . He was certain the two men were his sons . Their mother , Zubeidat Tsarnaeva , the aunt remembered , grabbed the television . `` It ca n't be , it ca n't be happening , '' she screamed . `` I do n't believe it . Children are dead ! '' Earlier that week , Zubeidat had been worried for her sons after hearing about the explosions . When she asked how they were doing in a phone conversation , the brothers said they loved her and that everything was `` pretty normal , '' Suleimanova said . `` Mommy , we are totally fine , '' they said , according to Suleimanova . `` We miss your warmth and your caress . '' Suspect 's wife 'very distraught ' Russia 's fight with Islamic militants . In a building on the other side of the city , the walls are still scarred from a fierce gunbattle between Russian security forces and Islamist militants that erupted last year . Fallen cinder blocks litter the ground inside . Neighbors told CNN that Abu Dujana and the other young men who once lived in the building seemed peaceful and ordinary . But in late December 2012 , authorities brought in an armored vehicle to kill Abu Dujana , whose real name was Gadzhimurad Dolgatov . There are no clues in the rubble left behind that offer answers to a troubling question : Why did Tsarnaev 's YouTube page link to the rants of the militant who died here ? In August 2012 , soon after returning from Russia to the United States , Tsarnaev apparently created a YouTube channel with links to a number of videos . Two videos under a category labeled `` Terrorists '' have since been deleted . It 's not clear when or by whom . One of those videos showed Abu Dujana , who led a small militant group that had links to the most potent Islamist group in the region . U.S. officials told CNN analyst Tom Fuentes on Sunday they have found no further connection between Tsarnaev and Abu Dujana , but the investigation into his activities overseas continues . In 2011 , before his visit to Russia , Moscow asked the FBI to investigate Tamerlan Tsarnaev in the United States , according to the FBI . `` The request stated that it was based on information that he was a follower of radical Islam and a strong believer , and that he had changed drastically since 2010 as he prepared to leave the United States for travel to the country 's region to join unspecified underground groups , '' the FBI said in a statement . Some details have also emerged about what Tsarnaev did after he returned from Russia , including a January incident at a mosque in Cambridge , Massachusetts . During a sermon about gaining inspiration from the story of slain civil rights leader Martin Luther King Jr. , Tsarnaev interrupted the preacher , the Islamic Society of Boston said in a statement Monday . Tsarnaev stood up , shouted at the preacher , accused him of `` contaminating people 's mind '' and called him a hypocrite , the society said , citing accounts from congregants . Some members of the congregation shouted back at Tsarnaev , telling him to `` leave now . '' Leaders of the mosque later told him he would no longer be welcome at the mosque if he continued to interrupt sermons . At future prayers , he was quiet . Suspects : An immigrant journey that went off track .
Aunt of alleged Boston bomber Tamerlan Tsarnaev speaks with Tsarnaev in Tsarnaev . She sheds light on Tsarnaev 's Islamist visit from December 2012 . He visited town where an Russian militant was killed in December 2012 . A video of the militant was posted , then removed from Tsarnaev 's YouTube channel .