Zubeidat Tsarnaeva

Zubeidat Tsarnaeva's household authority and influence on Tamerlan were subjects of the defense's penalty-phase presentation. Elmirza Khozhugov described her as having greater authority than Anzor, recalled Tamerlan's strong attachment to her, and said she welcomed Misha's religious and political conversations. Her sister and niece recalled her change from fashionable clothing to black clothing and a hijab, which they found unfamiliar within their family. In his opening statement, David Bruck argued that her religious influence, family instability, and the parents' departures helped strengthen Tamerlan's authority over Dzhokhar.

Documentary evidence concerning her also prompted a dispute over reliability. The defense sought to use Russian-supplied information and a purported message from Zubeidat as evidence of radicalization; prosecutors challenged their provenance and warned that they could mislead the jury. That exchange did not resolve admission of the disputed message. Separately, reports read to the jury described Russian allegations concerning Zubeidat and Tamerlan, interviews of Tamerlan and his parents, and an FBI assessment of Tamerlan closed in 2011 after finding no terrorism nexus.