Dzhokhar Tsarnaev is pictured in this handout photo presented as evidence by the U.S. Attorney’s Office in Boston, Massachusetts on March 23, 2015. Tsarnaev was heavily influenced by al Qaeda literature and lectures, some of which was found on his laptop, a counterterrorism expert testified at his trial on March 23, 2015. REUTERS/U.S. Attorney’s Office in Boston/Handout via Reuters FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS – RTR4UK50