BOSTON, MA - APRIL 6: A Boston Police Officer stands guard at a checkpoint on the road to John Joseph Moakley United States Courthouse on April 6, 2015 in Boston, Massachusetts. Dzhokhar Tsarnaev, 21, has pled not guilty to 30 charges related to his involvement in the 2013 bombing, which resulted in three deaths and over 250 injuries. (Photo by Scott Eisen/Getty Images)