Christian Fierabend

Christian Fierabend testified for the prosecution on Day 39 as an FBI special agent who participated in the Marathon bombing investigation. He compared pressure-cooker and BB purchase records with portable GPS data, while explaining that those comparisons did not identify the vehicles, occupants, or purchasers.

On direct examination, Fierabend described a January 31 purchase of six-quart and four-quart pressure cookers shortly before a recorded stop near Square One Mall ended. March 6 Walmart BB receipts also corresponded to New Hampshire stops. Relevant purchase surveillance was unavailable, and he could not connect a separate March 17 cooker sale to the Boylston Street bombing. He also described radio-controlled equipment records associated with Tamerlan Tsarnaev and a wallet receipt for Ful and JanSport backpacks. Although those brands were recovered at the Marathon Sports explosion site and Laurel Street, he did not identify the recovered items as the particular backpacks purchased.

Under cross-examination by Timothy Watkins, Fierabend confirmed that Target surveillance showed one person selecting and purchasing two backpacks. He described the shopper as closely resembling Tamerlan and said he believed the close-up showed Tamerlan. He did not know exactly how agents verified the receipt, but agreed that the displayed transaction log matched its items, payment amount, and SKU numbers. Questions about vehicle searches also elicited qualified recollections about gloves and trace filters; no laboratory findings were discussed.

On redirect, Fierabend confirmed that the Honda Odyssey was registered to Anzor Tsarnaev and the Honda CR-V to Tamerlan. He believed the wallet had been found in a Honda Civic but did not know who owned that vehicle. He acknowledged that the examined evidence did not establish who drove the vehicles, placed items inside them, or used them at particular times.