Emir Muaz , a Dagestan insurgent fighting in the Caucasus region , was killed in 2009 . 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 . Comment: Official to CNN : ` ` There 's no evidence why he wanted to change his name ''
Emir Muaz , a Dagestan insurgent fighting in the Caucasus region , was killed in 2009 . Comment: Official to CNN : `` There 's no evidence why he wanted to change his name ''