Anzor Tsarnaev

Anzor Tsarnaev figured in the defense's penalty-phase presentation through testimony and medical records concerning his psychiatric illness and functional limitations. David Bruck argued that Anzor's illness and departure for Russia helped leave Tamerlan with greater authority over Dzhokhar. Psychiatrist Alexander Niss described approximately 28 treatment visits during 2003–2005, a PTSD diagnosis, cognitive impairment and a later additional diagnosis of encephalopathy. He reported partial improvement with medication but continuing problems, and gave his opinion that Anzor could not work. Redacted treatment records were admitted as Defense Exhibit 3509E. Sonya Petri later read selected medical-record entries describing psychiatric symptoms before an August 2009 assault, a skull fracture and hemorrhage, surgery and subsequent impairments. An April 2012 physician's letter stated that Anzor could not work and needed constant supervision and support. Petri presented these clinical statements as a document reader, not a treating clinician; her summary was admitted as Exhibit 3523. Niss's testimony did not establish a psychiatric condition in Dzhokhar or a causal connection to his conduct.

Anzor also appeared in testimony about vehicle evidence. Christian Fierabend confirmed that a searched Honda Odyssey was registered to him and discussed trace filters believed to have been sent from the vehicles for laboratory analysis. On redirect, Fierabend acknowledged that the exhibits and data did not establish who drove the vehicles, placed items inside them or used them at particular times. Registration therefore did not identify Anzor as the person responsible for those activities.