April 15, 2013: emergency personnel assist a wounded person on the sidewalk after an explosion at the 2013 Boston Marathon AP
April 19, 2013 - Boston, Massachusetts, U.S. - Thousands take to the streets of the Boston area after Marathon Bombing suspect two D. Tsarnaev was captured in Watertown following a 24-hour chase and shootout. ZUMAPRESS.COM/MCT
Officials wearing tactical gear stand near an armored vehicle as they search an apartment building for one of two suspects in the Boston Marathon bombing, in Watertown, Mass. AP
An FBI agent goes door-to-door evacuating residents of Norfolk Street as investigators search for a suspect in the Boston Marathon bombings, in Cambridge, Mass., AP
Police in tactical gear surround an apartment building while looking for a suspect in the Boston Marathon bombings in Watertown, Mass., ASSOCIATED PRESS
Boston Police released this new photo of a man they referred to as "Suspect #2."
The FBI has released photos of two men, suspects one and two, in the Boston Marathon bombings. FBI.gov