Steven A. Kimball

FBI agent Steven A. Kimball testified for the prosecution about Twitter accounts attributed to Dzhokhar Tsarnaev. On Day 29, he described finding J_tsar through open-source media and public tips, locating Al_FirdausiA through account-following links, and connecting both accounts to the defendant through associated email records. He said both creation IP addresses resolved to the University of Massachusetts Dartmouth and that publicly collected posts matched Twitter's search-warrant returns. Subscriber records, tweet exhibits and a whole-page screenshot were admitted without defense objection. The presentation included posts before and after the bombing and religious posts recommending Anwar Awlaki, while Kimball acknowledged limits on his understanding of some posts.

On Day 30, Miriam Conrad questioned whether the selected tweets conveyed their surrounding context. Kimball confirmed that the prosecution team selected approximately 45 posts from the J_tsar account's 1,080 tweets, with very little input from him. He acknowledged omitted follow-up posts about respecting others' beliefs and writing a horoscope, alongside everyday subjects such as food, sleep and studying. He could not explain account updates after Tsarnaev's arrest and did not know many cultural references Conrad proposed. Over prosecution objections, the Court admitted the complete J_tsar account, which Conrad offered for context rather than the truth of its contents.

On redirect, Kimball confirmed that all Al_FirdausiA tweets had been introduced, that J_tsar covered more topics, and that both accounts were used during a period in March. He confirmed that a post referring to September 10th was dated March 14, 2013, and that April 17 was the last tweet date on either account. His information about Marathon attendance came from colleagues; the Court sustained objections limiting that questioning. The Court declined another defense question and deferred Conrad's requested proffer until a break.