April 15, 2013
This photo released by the FBI shows who the FBI was calling Suspect No. 1, in black cap, and Suspect No. 2, in white cap, walking through the crowd in Boston on April 15 before the explosions at the Boston Marathon. Law enforcement officials identified the suspect still on the loose as Dzhokhar Tsarnaev, 19, of Cambridge, Mass. His brother and alleged accomplice in the bombings, Tamerlan Tsarnaev, 26, was identified as the man killed during an encounter with police after an armed carjacking of a Mercedes SUV in Cambridge.