A few months before the Boston bombings , the suspected mastermind of the terror attack , Tamerlan Tsarnaev , wanted to change his name , a U.S. government official told CNN Wednesday . Tsarnaev , who was shot and killed in a massive manhunt , made an interesting choice for his new name . He wrote that he wanted to switch his first name to Muaz , the last name of Emir Muaz -- a Dagestan insurgent fighting in the Caucasus region of Russia , the official added . Muaz was killed in 2009 . Tamerlan Tsarnaev , the big brother of accused bomber Dzhokhar Tsarnaev , filed that request with U.S. immigration on January 23 , 2013 , as part of his application to become a naturalized U.S. citizen . His brother , Dzhokhar , had already become a naturalized citizen . `` We do n't know why , '' the official says . `` There 's no evidence why he wanted to change his name . '' Whether it was another indication of his radicalization that led to the marathon bombing is speculation , according to the source . The story was first reported in the Wednesday edition of the Los Angeles Times . The year before the April 15 , 2013 , bombing , Tamerlan Tsarnaev traveled to the restive Dagestan region , hoping to meet with Canadian boxer-turned-jihadist William Plotnikov . Russian troops killed Plotnikov in July 2012 while Tsarnaev was in the region . It 's unclear whether the two men ever came face to face . Tsarnaev flew out of Dagestan two days after Plotnikov was killed and investigators have been looking into whether Tsarnaev left because of Plotnikov 's death , according to another source briefed on the investigation . Authorities also have been investigating whether Tsarnaev had any contact with another militant , Mahmoud Mansur Nidal . The 18-year-old was killed by Russian forces in May 2012 during a gun battle in Makhachkala , Dagestan 's capital . As part of the naturalization process , a form requires a signature acknowledging the applicant will swear allegiance to the United State and might be required to serve in the military . Instead , the official says Tsarnaev printed his first and last name , but crossed out `` Tamerlan '' and changed it to `` Muaz . '' According to the website www.thinkbabynames.com , the name Tamerlan is derived from Tamerlane , the feared 14th-century warrior who conquered parts of the Middle East and Central Asia . Tamerlane , the name used in the epic Edgar Allan Poe poem , is now more commonly called Timur by historians . Four things we 've learned about the Boston bombings . Jeff Bauman , bombing survivor , engaged and expecting a child .
Emir Muaz , a Dagestan insurgent fighting in the Caucasus region , was killed in 2009 . Tamerlan Tsarnaev filed forms seeking use the fighter 's last name as his first name . Official to CNN : `` There 's no evidence why he wanted to change his name ''