With Tsarnaev case, civic duty may impose a heavy burden ← Related Article Visit The Boston Globe Share on Twitter Share on Facebook Comment on this Scroll to top of page Nearly two years after the Boston Marathon tragedy, the trial of one of the accused bombers has begun. John Tlumacki/globe Staff Karen Brassard, a victim of the bombing, departed the courthouse after the morning session. Jane Flavell Collins/Reuters Dzhokhar Tsarnaev is seen in a court room sketch. John Tlumacki/globe Staff The police presence was heavy outside the courthouse. John Tlumacki/globe Staff Defense attorneys Timothy Watkins and William Flick departed the courthouse. John tlumacki/Globe Staff A heavily armed Coast Guard boat patrolled the waters outside the court. David L. Ryan/Globe Staff Security was tight around the courthouse. John Tlumacki/Globe Staff The trial of the accused Marathon bomber opens today. Gretchen Ertl/Reuters A potential juror entered the courthouse ahead of jury selection. Michael Dwyer/Associated Press The media lined up outside the court. Michael Dwyer/Associated Press A protester held a sign outside the courthouse. David L. Ryan/Globe Staff Security could be seen outside Moakley federal courthouse early Monday morning. David L. Ryan/globe Staff Media cameras were set up outside the courthouse.