Michelle Gamble

Michelle Gamble testified as an FBI field photographer, using investigation photographs, surveillance footage, receipts, and phone records to describe the second bombing site and Dzhokhar Tsarnaev's movements. On Day 41, she identified his backpack, blast damage, and the locations of Lingzi Lu's and Martin Richard's bodies. She compared a SIM-card receipt naming Jahar Tsarni with an earlier backpack-purchase receipt and compared surveillance timing with phone records. Her proposed 20-second adjustment to the Forum video's timestamps depended on the race clock being accurate; the court allowed arithmetic using counsel's supplied starting time after sustaining foundation objections.

During cross-examination, Miriam Conrad tested the limits of those comparisons and Gamble's location diagram. Gamble acknowledged that the diagram depicted a minute before the second explosion and omitted nearby people, including Bill Richard, at the government's direction. She agreed that phone-record duration began with dialing and did not establish conversation length. Photograph metadata corrected her initial belief about one image's time to 2:49 p.m. She confirmed backpack placement around 2:45 p.m. and Tsarnaev's subsequent movement away, but rejected the suggestion that he was no longer visible immediately before the second blast.

On redirect, Gamble said the children remained in substantially the same positions until the first explosion, when people moved, and that Tsarnaev was almost off screen at the second explosion. The court sustained objections to questions seeking inferences about preparing to detonate a bomb and looking back; Gamble gave no answers to those questions. On recross, she agreed that Tsarnaev began walking away immediately after the first blast and added that some girls did too. An earlier photograph taken around 2:37 p.m. was admitted.

The defense then recalled Gamble about searches. She confirmed that she photographed the May 5, 2013 search of 410 Norfolk Street and, using a sketch, identified the wiring book's recovery location beneath the living-room couch. The court admitted the packaged book and its photograph, but excluded a proposed recovery-list extract and found inadequate foundation to refresh her recollection about a July property search. Gamble did not remember the book or know whether vacuum samples reached the laboratory. On prosecution cross-examination, she clarified that she was a field photographer, not an FBI agent, and authenticated a room photograph that the court admitted.

On Day 51, during the penalty phase, Gamble explained a full-size photographic grate reproduction made by measuring recovered sections and duplicating one section. Over defense objections, the court admitted it and allowed a demonstration. Her estimate of about three and a half feet measured the blast site's distance from Martin Richard's position in a photograph, not his independently established position at the explosion. She also explained synchronizing Atlantic Fish Company audio with silent Forum surveillance footage. The combined recording was admitted and played, along with admission of three Richard family photographs and highlighted surveillance footage. The defense asked no cross-examination questions.