Relatives described Tamerlan Tsarnaev, an ethnic Chechen, as having become a more devout Muslim in the last two years or so. An aunt, Maret Tsarnaeva, told reporters Friday that he had recently started praying five time a day.

Chechnya is a predominantly Muslim region of Russia; Tsarnaev spent six months in Russia beginning in January 2012, during which a relative told ABC News an uncles kicked him out of the house for having "increasingly extremist" views.