William D. Weinreb

William D. Weinreb presented the prosecution's argument that Dzhokhar Tsarnaev knowingly acted with his brother in the bombings and subsequent crimes, rather than merely following Tamerlan. His opening connected that allegation to surveillance, physical evidence and an asserted ideological motive. During jury selection, he distinguished opposition to capital punishment from an inability to consider imposing it and sought cause exclusions on that basis. The court did not invariably accept those requests: it denied the government's challenge to Juror 54.

Weinreb developed the visual chronology through evidence-collection and authentication witnesses, then examinations connecting surveillance, backpacks and phone records. On redirect, Anthony Imel retained qualifications about timestamps while placing the brothers' call before the explosion. Weinreb also authenticated retail and fitness-center evidence documenting post-bombing activity. With Michelle Gamble, he connected receipts, photographs and phone records to the second blast site and nearby people. The court sustained several redirect objections, including questions suggesting preparation to detonate a bomb or looking back while leaving; those questions received no answers. His responder and medical examinations developed blast effects, emergency triage and fatal injuries. The court permitted Jennifer Hammers's estimate that Krystle Campbell survived for seconds to approximately a minute over defense objections.

For the events surrounding Officer Collier's death, Weinreb presented MIT surveillance and Nathan Harman's identification of the defendant leaning into a police cruiser, including Harman's qualified recollection of a hat. Gas-station authentication and police-response testimony developed the carjacking sequence and efforts to locate the Mercedes. In Watertown, John MacLellan identified the defendant as a bomb thrower and Mercedes driver but could not identify who fired the gun. Weinreb later questioned David Henneberry about discovering blood and a motionless person in his boat, and about writing and blood that had not been there when he stored it.

Weinreb's forensic examinations connected fingerprints to vehicles, ammunition and recovered items, and Sean Collier's DNA to exterior glove samples and Honda keys. He used recovery questions to establish bomb-debris exhibits, compare pressure-cooker characteristics across scenes and describe shrapnel distribution. Scene-mapping testimony also preserved limits on vehicle placement. Purchase-and-GPS comparisons traced pressure cookers and BBs without identifying the purchasers; redirect likewise did not establish who used vehicles or placed items inside them. Against defense fingerprint evidence, Weinreb elicited from Elena Graff that absent prints do not exclude handling, both brothers' prints were on the bomb recovered from the Mercedes, and contact could not be dated. In guilt-phase rebuttal, he argued that differing roles did not negate partnership, acknowledged that the prosecution did not know who shot Collier, and requested guilty verdicts on all 30 counts. These were arguments, not findings.

In the penalty phase, Weinreb used family photographs to elicit memories of Sean Collier and continuing loss among relatives and colleagues. He questioned Marc Fucarile about lasting injuries and authenticated treatment X-rays, while returning to Gamble for blast-distance measurements and visual exhibits. He supported a narrowed presentation of individually photographed amputation survivors, which the court allowed over defense objections. He also opposed evidence of Tamerlan's alleged involvement in the Waltham killings, arguing that changing accounts, unavailable cross-examination and a collateral inquiry created reliability and distraction problems. That hearing contained no ruling; the court later excluded the Waltham events.

Weinreb's mitigation cross-examinations tested how much acquaintances and relatives knew about the brothers' relationship, Dzhokhar's independence and private beliefs. He elicited limited contact, leadership experience and knowledge gaps, and had Sonya Petri read an additional interview-report passage concerning Dzhokhar's own remarks about school, Russia and America. The court barred questions contrasting Raisat Suleimanova's childhood memories with the bombings. Weinreb challenged Michel Reynolds's cultural explanations through an earlier article; Reynolds said reviewing the evidence had changed his opinion, and the court barred a family-specific recross question beyond redirect. Weinreb sought limits on Sister Helen Prejean's remorse opinion and questioned her death-penalty advocacy and organizational funding; the court allowed the lay opinion with restrictions. On prison conditions, his requested response to a snowy ADX photograph was limited to heating and airport access. He advocated detailed aggravating-factor instructions and later joined the defense proposal to refer jurors to existing personal-actions-and-intent language. His penalty rebuttal urged death and disputed mitigation based on influence, youth and remorse. The court overruled repeated objections and subsequently denied a defense reply and curative instruction. At sentencing, he requested death sentences on six counts, additional imprisonment and financial orders.